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Lab Manual

Anatomy and Physiology
LabPaq: AP-1
14 Small-Scale Experiments for Independent Study

Published by Hands-On Labs, Inc.

Anatomy and Physiology: Independent Laboratory Exercises for the First Semester
Designed to accompany Anatomy & Physiology LabPaq AP-1 062211

LabPaq® is a registered trademark of Hands-On Labs, Inc. (HOL). The LabPaq referenced in this manual is produced by Hands-On Labs, Inc. which holds and reserves all copyrights on the intellectual properties associated with the LabPaq’s unique design, assembly, and learning experiences. The laboratory manual included with a LabPaq is intended for the sole use by that LabPaq’s original purchaser and may not be reused without a LabPaq or by others without the specific
written consent of HOL. No portion of any LabPaq manual’s materials may be reproduced, transmitted or distributed to others in any manner, nor may they be downloaded to any public or privately shared systems or servers without the express written consent of HOL. No changes may be made in any LabPaq materials without the express written consent of HOL. HOL has invested years of research and development into these materials, reserves all rights related to them, and retains the right to impose substantial penalties for any misuse. Author: Published by: Laszlo Vass, Ed.D. Hands-On Labs, Inc. 3880 S. Windermere St. Englewood, CO 80110 www.LabPaq.com Denver Area: 303-679-6252 Toll-free, long-distance: 866-206-0773 [e-mail] Printed in the United States of America. ISBN: 978-1-866151-17-8 Although the author and publisher have exhaustively researched all sources to ensure the accuracy and completeness of the information contained in this book, we assume no responsibility for errors, inaccuracies, omissions or any other inconsistency herein. Any slight of people, organizations, materials, or products is unintentional. The A&P LabPaq AP-1 produced and supplied by Hands-On Labs, Inc., is a collection of laboratory exercises, equipment, materials and chemicals specifically packaged to accompany this manual. Easily procured items are supplied by the student. Citation of sources of materials or use of copyrighted or registered names of materials is provided for information purposes only. Use of this information does not necessarily indicate endorsement or approval of the sources or names.

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Table of Contents
Introduction ..............................................................................................................................4 Important Information to Help Students Study Science .....................................................4 WELCOME TO THE WORLD OF SCIENCE! ................................................................................4 Laboratory Equipment and Techniques ........................................................................... 13 Use, Disposal, and Cleaning Instructions for Common Materials ................................... 19 HOW TO WRITE LAB NOTES AND LAB REPORTS .................................................................. 21 Lab Notes .......................................................................................................................... 21 Lab Reports ....................................................................................................................... 23 Laboratory Drawings ......................................................................................................... 27 Visual Presentation of Data .............................................................................................. 28 Computer Graphing Using MS Excel ................................................................................. 32 SAFETY CONCERNS ............................................................................................................... 40 Basic Safety Guidelines .................................................................................................... 41 Material Safety Data Sheets ............................................................................................. 46 Science Lab Safety Reinforcement Agreement ............................................................... 50 EXPERIMENTS 1. Using the Microscope ................................................................................................ 53 2. An Overview of Anatomy ............................................................................................ 68 3. Histology ..................................................................................................................... 88 4. Classification of Body Membranes .......................................................................... 102 5. The Integumentary System ...................................................................................... 114 6. Overview of the Skeletal System ............................................................................. 126 7. The Axial and Appendicular Skeleton ...................................................................... 142 8. Joints and Body Movements.................................................................................... 157 9. Organization of Muscle Tissue ................................................................................ 173 10.Gross Anatomy of the Muscular System ................................................................. 183 11.Muscle Physiology ................................................................................................... 206 12.Organization of Nervous Tissue .............................................................................. 226 13.Gross Anatomy of the Central Nervous System ..................................................... 240 14.Reflex and Sensory Physiology ................................................................................ 263 APPENDIX Final Cleanup Instructions .................................................................................................. 295

Introduction
Important Information to Help Students Study Science
Version 09.3.03

WELCOME TO THE WORLD OF SCIENCE!
Don't be afraid to take science courses.
When you complete them, you will be very proud of yourself and will wonder why you were ever afraid of the “S” word – Science! After their first science course most students say they thoroughly enjoyed it, learned a lot of useful information relevant to their personal lives and careers, and only regret not having studied science sooner. Science is not some mystery subject comprehended only by eggheads. Science is simply a way of learning about our natural world and how it works by testing ideas and making observations. Learning about the characteristics of the natural world, how those characteristics change, and how those characteristics interact with each other make it easier to understand ourselves and our physical environment and to make the multitude of personal and global decisions that affect our lives and our planet. Plus, science credits on an academic transcript are impressive, and your science knowledge may create some unique job opportunities. All sciences revolve around the study of natural phenomena and require hands-on physical laboratory experiences to permit and encourage personal observations, discovery, creativity, and genuine learning. As increasing numbers of students embrace online and independent study courses, laboratory experiences must remain an integral part of science education. This lab manual’s author and publisher are science educators who welcome electronic technology as an effective tool to expand and
enhance instruction. However, technology can neither duplicate nor replace learning experiences afforded to students through traditional hands-on laboratory and field activities. This does not mean that some experiments cannot or should not be replaced or reinforced by computer simulations; but any course of science study must also provide sufficient hands-on laboratory and field experiences to:    Engage students in open-ended, investigative processes by using scientific problem solving. Provide application of concepts students have seen in their study materials which reinforce and clarify scientific principles and concepts. Involve multiple senses in three-dimensional rather than two-dimensional learning experiences that are important for greater retention of concepts and for accommodation of different leaning styles.
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Stimulate students to understand the nature of science including its unpredictability and complexity. Provide opportunities to engage in collaborative work and to model scientific attitudes and behavior. Develop mastery of techniques and skills needed for potential science, engineering, and technology careers. Ensure advanced placement science courses transfer to college credit.

The knowledge gained from science courses with strong laboratory components enables students to understand in practical and concrete ways their own physical makeup, the functioning of the natural world around them, and contemporary scientific and environmental issues. It is only by maintaining hands-on laboratory experiences in our curricula that the brightest and most promising students will be stimulated to learn scientific concepts and avoid being turned-off by lecture- and textbook-only approaches. Physical experimentation may offer some students their only opportunity to experience a science laboratory environment. All students – as potential voters, parents, teachers, leaders, and informed citizens – will benefit from a well-rounded education that includes science laboratory experiences, when it is time for them to make sound decisions affecting the future of their country and the world. 19th century scientist, Ira Remsen (1846-1927) on the subject of Experimentation:

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This lab manual can be used by all students, regardless of the laboratory facilities available to them. The experiments are based on the principles of micro- and small-scale science which have been successfully used in campus laboratories for decades. LabPaq’s microand small-scale experiments can also be performed at home, in a dorm room, or at a small learning center that lacks a formal laboratory.

What are Micro- and Small-scale Experiments?
You may be among the growing number of students to take a full-credit, laboratory science course through independent study, due to the development and perfection of micro-scale and small-scale experimentation techniques over the past half century. While experimentation on any scale is foundational to fully understanding science concepts, science courses in the past have required experimentation to be performed in the campus laboratory due to the potential hazards inherent in traditional experimentation. Potential hazards, increasing chemical, specimen, and science equipment costs, and environmental concerns made high schools, colleges, and universities reexamine the traditional laboratory methods used to teach science. Scientists began to scale down the quantities of materials and the size of equipment used in experiments and found reaction results remained unchanged. Over time, more and more traditional science experiments were redesigned to be performed on micro and small scales. Educational institutions eventually recognized that the scientific reaction, not the size of the reaction, facilitates learning. Successive comparative assessments have proven that students’ learning is not impaired by studying small-sized reactions. Many assessments even suggest that science learning is enhanced by small-scale experimentation. The primary pioneer and most prominent contributor to micro- and small-scale experimentation was Dr. Hubert Alyea, a chemistry professor at Princeton University, who began utilizing micro-scale experiments in the 1950s. Dr. Alyea reformatted numerous chemistry experiments and also designed many of the techniques and equipment used in micro- and small-scale science today. In the mid-1990s, Dr. Peter Jeschofnig of Colorado Mountain College pioneered the development of LabPaq’s academically aligned, small-scale experiments that can be performed at home. Hands-On Labs, Inc. has subsequently proven that students can actually perform LabPaq's rigorous science experiments at home and still achieve an equivalent, if not higher, level of learning than their campus-based peers.

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The Organization of this Lab Manual
Before proceeding with your experiments, please thoroughly read and understand each section of this lab manual, so you understand what is expected of you.
Introduction and How to Study Science: These sections include important information about general scientific subject matter and specific information about effectively studying science and conducting science experiments. Read these sections carefully and take them to heart! How to Perform an Experiment and Laboratory Equipment and Techniques: Adhering to the procedures described in these sections will greatly facilitate experimental activities. The laboratory techniques and equipment described primarily apply to full-scale experiments and formal laboratories; however, knowledge of these items is important to a basic understanding of science and is relevant to home-based experimentation. How to Write Lab Notes and Lab Reports: Like all serious scientists, you must record formal notes detailing your activities, observations, and findings for each experiment. These notes will reinforce your learning experiences and science knowledge and provide the basis from which you will prepare Lab Reports for your instructor. This section explains how these documents should be organized and prepared. Safety Concerns: The Basic Safety Guidelines and Safety Reinforcement Agreement are the most important sections of this lab manual and should be reviewed before each experiment. The safety sections are relevant to both laboratory and
non-laboratory experimentation. The guidelines describe potential hazards as well as basic safety equipment and safety procedures designed to avoid such hazards. Required Equipment and Supplies: If you are performing these experiments in a nonlaboratory setting, you must obtain the LabPaq specifically designed to accompany this lab manual. The LabPaq includes all the basic equipment and supplies needed to complete the experiments, except for minor items usually found in the average home or obtained at local stores. At the beginning of each experiment you will find a materials section listing which items are found in the LabPaq and which items you will need to provide. Review this list carefully before you begin an experiment to ensure you have all required items. Experiments: The experiments included in this lab manual were specifically selected to accompany related course materials for a traditional academic term. These experiments emphasize a hands-on, experimental approach for gaining a sound understanding of scientific principles. The lab manual’s rigorous Lab Report requirements help reinforce and communicate your understanding of each experiment’s related science principles and strengthen your communication skills. This traditional, scientific method approach to learning science reflects the teaching philosophy of the authors, Hands-On Labs, Inc., and science educators around the globe.

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HOW TO STUDY SCIENCE
It is unfortunate that many people develop a fear of science somewhere early in life. Yes, the natural sciences are not the easiest subjects to learn; but neither are they the hardest. Like in any other academic endeavor, if you responsibly apply yourself, conscientiously study your course materials, and thoughtfully complete your assignments, you will learn the material. Following are some hints for effectively studying science and any other subject, both on or off campus. Plan to Study: You must schedule a specific time and establish a specific place in which to seriously devote yourself to your studies. Think of studying like you would think of a job. Jobs have specific times and places in which to get the work done, and studying should be no different. Just as television, friends, and other distractions are not permitted on a job, they should not be permitted to interfere with your studies. If you want to do something well, you must be serious about it, and you cannot learn when you are distracted. Only after you have finished your studies should you allow time for distractions. Get in the Right Frame of Mind: Think positively about yourself and what you are doing. Put yourself in a positive frame of mind to enjoy what you are about to learn, and then get to work. Organize any materials and equipment you will need in advance so you don't have to interrupt your work later. Read your syllabus and any other instructions and know exactly what your assignment is and what is expected of you. Mentally review what you have already learned. Write down any questions you have, and then review previous materials to answer those questions. Move on, if you haven't found the answer after a reasonable amount of time and effort. The question will germinate inside your mind, and the answer will probably present itself as you continue your studies. If not, discuss the question later with your instructor. Be Active with the Material: Learning is reinforced by relevant activity. When studying, feel free to talk to yourself, scribble notes, draw pictures, pace out a problem, or tap out a formula. The more physically active things you do with your study materials, the better you will learn. Have highlighters, pencils, and note pads handy. Highlight important data, read it out loud, and make notes. If there is a concept you are having problems with, stand up and pace while you think it through. Try to see the action taking place in your mind. Throughout your day, try to recall things you have recently learned, incorporate them into your conversations, and teach them to friends. These activities will help to imprint the related information in your brain and move you from simple knowledge to true understanding of the subject matter.

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Do the Work and Think about What You Are Doing: Sure, there are times when you might get away with taking a shortcut in your studies, but in doing so you will probably shortchange yourself. The things we really learn are the things we discover ourselves, which is why we don't learn as much from simple lectures, passive videos, or someone simply telling us the answers to our questions. Discovery learning – figuring things out for ourselves – is the most effective and long-lasting form of learning. When you have an assignment, don't just go through the motions. Enjoy your work, think about what you are doing, be curious, ask yourself questions, examine your results, and consider the implications of your findings. These critical thinking techniques will improve and enrich your learning process. When you complete your assignments independently and thoroughly, you will be genuinely knowledgeable and can be very proud of yourself.

How to Study Independently
There is no denying that learning through any method of independent study is very different from learning through classes held in traditional classrooms. It takes a great deal of personal motivation and discipline to succeed in a course of independent study where there are no instructors or fellow students to give you structure and feedback. These problems are not insurmountable, and meeting the challenges of independent study can provide tremendous personal satisfaction. The key to successful independent study is having a personal study plan and the personal discipline to stick to that plan. Properly Use Your Learning Tools: The basic tools for web courses and other distance learning methods are often similar, consisting of computer software, videos, textbooks, and study guides. Check with your course instructor to make sure you acquire all the materials you will need. You can obtain these items from campus bookstores, libraries, or the Internet. Related course lectures and videos may even be broadcast on your local public and educational television channels. If you choose to do your laboratory experimentation independently, you will need the special equipment and supplies described in this lab manual and contained in its companion LabPaq. For each study session, first work through the appropriate sections of your course materials, because these serve as a substitute for classroom lectures and demonstrations. Take notes as you would in a regular classroom. Actively work with any computer and text materials, carefully review your study guide, and complete all related assignments. If you do not feel confident about the material covered, repeat the previous steps until you do. It is wise to always review your previous work before proceeding to a new section to reinforce what you’ve previously learned and prepare you to better absorb new information. Actual experimenting is among the last things done in a laboratory session.

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Plan to Study: A normal science course with a laboratory component may require you to spend as many as 15 hours a week studying and completing your assignments. To really learn new material requires at least three hours of study time each week for each hour of course credit taken. This applies as equally to independent study as it does to regular classroom courses. On a school campus science students are usually in class for three hours and in the laboratory for two to three hours each week. Then, they still need at least nine hours to read their text and complete their assignments. Knowing approximately how much time is required will help you formulate a study plan at the beginning of the course. Schedule Your Time Wisely: The more often you interact with study materials and call them to mind, the more likely you are to reinforce and retain the information. It is much better to study in several short blocks of time rather than in one long, mind-numbing session. Accordingly, you should schedule several study periods throughout the week or during each day. Please do not try to do all of your study work on the weekends! You will burn yourself out, you won't learn as much, and you will probably end up feeling miserable about yourself and science too. Wise scheduling can prevent such unpleasantness and frustration. Choose the Right Place for Your Home Laboratory: The best place to perform at-home experiments will be determined by the nature of the individual experiments. However, this place is usually an uncluttered room where a door can be closed to keep out children and pets; a window or door can be opened for fresh air ventilation and fume exhaust; there is a source of running water for fire suppression and cleanup; and there is a counter or tabletop work surface. A kitchen usually meets all these requirements. Sometimes the bathroom works too, but it can be cramped and subject to interruptions. Review each experiment before starting any work to help you select the most appropriate work area. Because some of the equipment and supplies in your LabPaq may pose dangers to small children and animals, always keep safety in mind when selecting a work area, and always choose an area where you cannot be disturbed by children or pets. Use a Lab Partner: While the experiments in the LabPaq can be performed independently, it is often fun and useful to have a lab partner to discuss ideas with, help take measurements, and reinforce your learning process. Whether your partner is a parent, spouse, sibling, or friend, you will have to explain what you are doing, and in the process of teaching another, you will better teach yourself. Always review your experiments several days ahead of time so you have time to line up a partner if needed. Perform Internet Research: Students in today’s electronic information age are often unaware of how fortunate they are to have so much information available at the click of a mouse. Consider that researchers of the past had to physically go to libraries, search through card catalogs for possible sources of information, and wait weeks to receive books and journals that may not contain the information they needed. Then they had to begin their search all over again! Now you can find information in a matter of minutes.

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Since most courses today include online components, it is assumed that you have reasonable computer skills. If you make ample use of those skills and include online research as part of your study routine, you can greatly enhance your depth of learning as well as improve your grades. Keep a web browser open as you review your course materials and laboratory assignments. When you encounter words and concepts that you have difficulty fully understanding, perform a quick web search and review as many sites as needed until the definition or concept is clear in your mind. Web searches are especially valuable in science. For example, if you have difficulty with a concept, you can usually perform an image search that will help visually clarify the object of interest. Perform a text search to find descriptions and information from leading scientists at famous institutions all over the world. For unfamiliar terms, enter the word “define” plus the unfamiliar term into your search engine and a myriad of differently phrased definitions will be available to help you. This lab manual lists numerous respected websites that you may find useful, and you will undoubtedly find many more on your own. Rely only on trusted government and educational institutions as sources for valid research data. Be especially skeptical of and double-check information garnered from personal blogs and wiki sites like wikipedia.org, where anyone, regardless of their expertise or integrity, can post and edit information. As students all over the world are finding, the worldwide web is a treasure trove of information, but not all of it is valid! Finally, while website links in this lab manual were valid at the time of printing, many good websites become unavailable or change URLs. If this happens, simply go to one of the other sites listed or perform a web search for more current sites.

HOW TO PERFORM AN EXPERIMENT
Although each experiment is different, the process of preparing, performing, and recording an experiment is essentially the same. Read the Entire Experiment before You Start: Knowing what you are going to do before you do it will help you organize your work and be more effective and efficient. Review Basic Safety: Before beginning work on any experiment, reread the lab manual’s safety sections, try to foresee any potential hazards, and take appropriate steps to prevent safety problems. Organize Your Work Space, Equipment, and Materials: It is hard to organize your thoughts in a disorganized environment. Assemble all required equipment and supplies before you begin working.

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Outline Your Lab Notes: Outline the information needed for your Lab Notes and set up any required data tables before the experiment, to make it easier to enter observations and results as they occur. LabPaq CDs normally include a Report Assistant containing .rtf files of each experiment’s questions and data tables. These files can be copied and pasted into your Lab Notes to facilitate your compilation of data and text information. Perform the Experiment According to Instructions: Follow all directions precisely in sequential order. This is not the time to be creative. Do not attempt to improvise your own procedures! Think About What You Are Doing: Stop and give yourself time to reflect on what has happened in your experiment. What changes occurred? Why? What do they mean? How do they relate to the real world of science? This step can be the most fun and often creates "light bulb" experiences of understanding. Clean Up: Always clean your laboratory space and laboratory equipment immediately after use. Wipe down all work surfaces that may have been exposed to chemicals or dissection specimens. Blot any unused chemicals with a paper towel or flush them down the sink with generous amounts of water. Wrap dissection specimens in newspaper and plastic and place them in a sealed garbage can. Discard used pipets and other waste in your normal trash. Return cleaned equipment and supplies to their LabPaq box and store the box out of reach of children and pets. Complete Your Work: Complete your Lab Notes, answer the required questions, and prepare your Lab Report. If you have properly followed all the above steps, the conclusion will be easy.

Why Experimental Measurements Are Important:

We measure things to know something about them, to describe objects, and to understand phenomena. Experimental measurement is the cornerstone of the scientific method; thus, no theory or model of nature is tenable unless the results it predicts are measurable and in accordance with the experiment.

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Your primary tasks in a science laboratory course are to create experimentally measured values, compare your results to accepted theoretical or measured values, and gain a full understanding of scientific concepts. This is true for experiments done both inside and outside of a formal laboratory. Each experiment is predicated upon a theory of scientific principle and represents a test of that theory through experimentation, observation, measurements, and analysis.

Laboratory Equipment and Techniques
While many of these techniques and equipment are most applicable to specific science disciplines in formal laboratory facilities, knowledge of these items is often required for the study of other science disciplines and when working in a home laboratory. Dispensing Chemicals: To avoid contamination when pouring liquid chemicals from a reagent (ree-ey-juhnt) bottle with a glass stopper, hold the stopper in your fingers while carefully pouring the liquid into the desired container. When pouring from a screw-cap bottle, set the cap down on its top so that it does not become contaminated or contaminate anything. Be certain to put the correct cap on the bottle after use. Never pour excess chemicals back into a reagent bottle, because this may contaminate the reagents. If any liquid spills or drips from the bottle, clean it up immediately. To obtain samples of a powdered or crystalline solid from a container, it is best to pour the approximate amount of solid into a clean, dry beaker or onto a small piece of clean, creased paper for easy transport. Pour powders and crystals by tilting the container, gently shaking and rotating the solids up to the container lip, and allowing the solids to slowly fall out. If you pour too much solid, do not put any solid back in the container. Also, never put wooden splints, spatulas, or paper into a container of solids to avoid contamination. Dropping Chemicals: In micro-scale science, you use only small drops of chemicals, and it is extremely important that the drops are uniform in size and carefully observed. To ensure uniformity of drop size, use scissors to cut off the tip of the pipet perpendicular to the pipet body; cutting at an angle will distort drop sizes. Turn the pipet upside down so the dispensing chamber behind the dropper is full of liquid. Then hold the dropper in front of your eyes so you can carefully observe and count the number of drops dispensed as you slowly squeeze the pipet. You can see the incorrect (left) and correct (right) way to dispense drops. The pipet should be held in a vertical position at eye level to ensure drops are uniform in size and the correct drops are dispensed.

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Heating Chemicals: Heat solid and liquid chemicals with great care to prevent explosions and accidents. Liquids in Beakers: To heat liquids in beakers or flasks, ensure that these containers are well supported above the heat source. Generally, the beaker or flask is placed on wire gauze supported by an iron support attached to a stand. The heat source is placed under the beaker or flask. Liquids in Test Tubes: When heating liquids in test tubes, always use a test tube holder. Evenly heat the test tube contents by carefully moving the test tube back and forth in the flame. Heat the test tube near the top of the liquid first; heating the test tube from the bottom may cause the liquid to boil and eject from the tube. Heating Sources for Small-scale Techniques: For micro- and small-scale science experimentation, the most commonly used heat sources are alcohol burners, candles, and burner fuel. Alcohol burners can be a problem because their flame is almost invisible, and they cannot be refilled while hot. Candles, while effective for heating small quantities of materials, tend to leave a sooty, carbon residue on the heated container that obstructs observations. Sterno and similar alcohol based fuels are very volatile and cannot be safely shipped; however, the Glycol-based fuel used in LabPaqs is safe to ship. Chafing dish (i.e., burner fuel) is actually the best of these alternatives because it has a visible flame, is easily extinguished, and does not leave excessive flame residue. Regardless of the type of burner used, never leave an ignited heat source unattended. Mass Measurement Equipment: Note that weighing scales are often called balances since weights are calculated using balance beams. Triple and quadruple beam balances are the most common measuring equipment found in laboratories. However, with today's precision technology, digital top-loading balances are becoming increasingly popular. Triple and Quadruple Beam Scale: These balances typically include a hanging pan and vary in their degree of accuracy. After the scale has been set at zero, the object to be weighed is placed in the hanging pan, and balancing weights are added or subtracted by moving a pointer across a horizontal bar scale. When exact scale is achieved, the pointer indicates the object’s mass. Digital Top Loading Balance: This scale is initially zeroed by pressing the zero button. If your are using weighing paper or a small beaker, first tare the paper or beaker by placing it on the scale and pressing the tare button. This will produce a zero reading, and the weight of the paper or beaker will be excluded from the weighing process. Hanging Spring Scales: Measurements are taken by suspending the item from a scale, often within a container. Spring scales are not easily tared, so the container weight should be separately calculated and subtracted from the combined weight of the item and the container.

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The Non-digital Analytical Balance: This instrument is very delicate, and the instructions for its use are quite detailed. Because of its extreme sensitivity, weighing on the analytical scale must be carried out in a closed chamber that is free from drafts. This instrument is seldom used by first-year science students. Volume Measurement Equipment: To obtain accurate measurements from any glass volume measurement container, such as a beaker or graduated cylinder, you must identify and correctly read a curved surface known as the meniscus. The meniscus of water and waterbased solutions concaves downward and is read at the very bottom of its curve. A mercury meniscus is convex and is read at the very top of its curve. There is no meniscus issue associated with plastic containers. Filtration Equipment: Gravity filtration is used to remove solid precipitates or suspended solids from a mixture. It works like a small funnel or spaghetti strainer, except that it is lined with fine, conical filter paper to trap the solids. After pouring a mixture into the filter from a beaker, use a special spatula, called a rubber policeman, to scrape any remaining solids from the beaker wall into the conical filter paper. Then, use a wash bottle to rinse residue from both the beaker and rubber policeman into the filter cone to ensure that all the mixture's particles pass through the filter. Suction filtration uses a vacuum to suck a mixture through a filter. It is much faster than but not always as efficient as gravity filtration. The required vacuum is usually created by the aspirator of a laboratory water faucet. Bunsen Burner: This old, tried-and-true heat source relies on the combustion of natural or bottled gas. To achieve the best flame, you must properly adjust the burner's gas inlet valve and air vent. Open the valves only halfway before lighting the burner. The safest way to light the burner is to bring a lighted match to the flame opening from the side, not the top. When the burner is lit, close the air vent and adjust the gas inlet valve until the flame is approximately 10 cm high. The flame should be luminous and yellow. Next, open the air vent until the flame becomes two concentric cones. The outer cone will be faintly colored and the inner cone will be blue. The hottest part of the flame is at the tip of the blue cone. Graduated Cylinder: Graduated cylinders are available in a wide range of sizes. To read a volume in a graduated cylinder, hold the cylinder at eye level so the contents level and you can directly view the meniscus. Looking at a meniscus from below or above will create parallax and cause a false reading. Always read any scale to the maximum degree possible, including an estimate of the last digit. Buret: Burets are long, graduated tubes usually used in titration. They have a stopcock or valve on the bottom that allows you to dispense liquids in individual drops and accurately measure the quantity dispensed. Use caution when opening the stopcock to ensure that only one drop is dispensed at a time. Pipet: Pipets are small tube-type containers with openings at one end if made of plastic or at both ends if made of glass. They come in a range of volumes and are generally used to transfer specific amounts of liquids from one container to another.

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Berel Pipet: These soft and flexible pipets are made of polyethylene plastic and are extensively used in LabPaqs. They have long, narrow tips and are used to deliver chemicals and to collect products. Berel pipets come in different sizes, and their tips can have different diameters and lengths. You can modify them to serve diverse purposes such as chemical scoops, gas generators, or reaction vessels. Volumetric Flask: Volumetric flasks are pear-shaped flasks with long necks used for the preparation of solutions whose concentrations need to be very accurate. Flasks come in a variety of sizes ranging from a few milliliters to several liters, and their volume levels are precisely marked. When the liquid level inside a volumetric flask is such that the meniscus lines up with the calibration mark on the neck, the volume of the liquid is exactly as stated. Unlike volumetric flasks, the markings on beakers, Erlenmeyer flasks, and most other laboratory containers are very good approximates but are not intended to be exact and precise volume measurements. Wash Bottles: These plastic squeeze bottles produce a small stream of water that can be easily dispensed as needed (e.g., washing out residue from a container). The bottles usually contain distilled or deionized water and are typically used to top off the last few milliliters of a vessel and avoid overfilling. In micro- and small-scale experimentation, plastic pipets are used for similar functions. Tissue Culture Well Plates: These microplates are plastic trays containing numerous shallow wells arranged in lettered rows and numbered columns. Similar to test tubes and beakers, you can use the wells to observe reactions, to temporarily store chemicals during experiments, and to hold pipets. The most commonly used plates are 24-well and 96-well. Distilled Water and Deionized Water: Tap water frequently contains ions that may interfere with the substances you are studying. To avoid such interference, use distilled or deionized water any time water is needed for dilution of concentration or the preparation of experimental solutions. Wash used glassware with soap, rinse with tap water, and rinse again with distilled water.

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Use, Disposal, and Cleaning Instructions for Common Materials
These procedures are not repeated for each experiment, because it is assumed students will always refer to them before beginning any experiment. Properly cleaning the laboratory after experimentation is a safety measure! Instrument Use  Small quantities of chemicals are usually packaged in thin stem pipets. The drop size dispensed from small dropper bottles is different from that of the pipets. Most experiments require pipet-sized drops. It may be necessary to squeeze a few drops of chemical from a dropper bottle into a well plate, and then use a clean, empty pipet to suck up and drop the chemical. Once dispensed, do not return chemicals to their dropper bottles as this could cause contamination. To avoid over-dispensing, squeeze out only a few drops of chemicals into a well plate at a time. Squeeze out more as needed. To use burner fuel, unscrew the cap, light the wick, and place the can under a burner stand. Extinguish the fuel by gently placing the cap over the flame to deprive it of oxygen. Leave the cap sitting loosely on top of the wick when you are not using the fuel in order to avoid unnecessary evaporation and ensure an ample supply of fuel for all experiments. Allow the fuel to cool completely before tightly screwing on the cap for storage. If you screw the cap on while the fuel is still hot, you may create a vacuum that will make it very difficult to reopen the fuel can in the future. To reseal a pipet, heat the tip of a metal knife and press the pipet tip onto the hot metal while twirling the bulb. Never simply hold a flame to the tip of the stem! To minimize contamination, avoid touching the surfaces of clean items that might later come in contact with test chemicals.

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Storage and Disposal  Items in LabPaq auxiliary bags are generally used multiple times or for several different experiments. Always clean and return unused auxiliary items to the bag after completing an experiment. Blot up used and leftover chemicals with paper towels and place in a garbage bin or flush down a drain using copious amounts of water. The quantities of chemicals used in LabPaqs are very small and should not negatively impact the environment or adversely affect private septic systems or public sewer systems. Discard non-chemical experimental items with household garbage but first wrap them in newspaper. Place these items in a securely covered trash container that cannot be accessed by children and animals.
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LabPaqs containing dissection specimens will usually contain specific information regarding their handling. After completion of any dissecting work, wrap dissection specimens in news or waste paper, seal in a plastic bag, and place in a closed trash bin for normal garbage disposal.

Cleaning Instructions  To clean a thin-stemmed plastic pipet, squeeze the bulb to draw up and then expel tap water from the bulb several times. Repeat this process with distilled water. Dry the pipet by repeatedly squeezing the bulb while tapping the tip on a clean paper towel. Then use gravity to help dry the pipet by forcefully swinging the pipet into a downward arch while squeezing the bulb. Lay the pipet on a clean paper towel or place it in a test tube stand and allow it to air dry. Use a mild liquid dishwashing detergent mixed with warm water to loosen solids or oils that adhere to experimental glassware, plastics, and equipment and to clean laboratory equipment and the laboratory area after an experiment. Use tap water to rinse washed items well and remove all traces of detergent. Use a soft cloth or a test tube brush to loosen and clean residue from the surfaces of experimental glassware, plastics, and equipment. Use a final rinse of distilled water to clean tap water mineral residue from newly washed items, especially beakers, cylinders, test tubes, and pipets. Dry test tubes by placing them upside down in the test tube rack. Air dry other items by placing them on paper towels, aluminum foil, or a clean dishtowel.

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Important Notice Regarding Chemical Disposal: Due to the minute quantities and diluted and/or neutralized chemicals used in LabPaqs, the disposal methods previously described are well within acceptable levels of disposal guidelines defined for the vast majority of local solid and wastewater regulations. Since regulations occasionally vary in some communities, you are advised to check with your local area waste authorities to confirm these disposal techniques are in compliance with local regulations and/or if you should seek assistance with disposal.

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HOW TO WRITE LAB NOTES AND LAB REPORTS
Generally two basic records are compiled during and from scientific experimentation. The first record is your Lab Notes which you will record as you perform your experiments. Entries in your lab notebook will be the basis for your second record, the Lab Report. The Lab Report formally summarizes the activities and findings of your experiment and is normally submitted to your instructor for grading.

Lab Notes
Scientists keep track of their experimental procedures and results as they work by recording Lab Notes in a journal-type notebook. In laboratories these notebooks are often read by colleagues, such as directors and other scientists working on a project. In some cases scientific notebooks have become evidence in court cases. Consequently, Lab Notes must be intelligible to others and include sufficient information so that the work performed can be replicated and there can be no doubt about the honesty and reliability of the data and the researcher. Notebooks appropriate for data recording are bound and have numbered pages that cannot be removed. Entries include all of your observations, actions, calculations, and conclusions related to each experiment. Never write data on pieces of scratch paper to transfer later, but always enter the data directly into the notebook. When you record erroneous data, neatly draw a light, diagonal line through the error, and write a brief explanation as to why you voided the data. Also record information you learn from an error. Mistakes can often be more useful than successes, and knowledge gained from them is valuable to future experimentation. As in campus-based science laboratories, independent study students are expected to keep a complete scientific notebook of their work which may or may not be periodically reviewed by the instructor. Paperbound 5x7 notebooks of graph paper work well as lab notebooks. Since it is not practical to send notebooks back and forth between instructors and students for each experiment, independent study students usually prepare formal Lab Reports and submit them along with their regular assignments to the instructor via email or fax. Lab Notes of experimental observations can be kept in many ways. Regardless of the procedure followed, the key question for deciding what kind of notes to keep is: Do I have a clear enough record that if I pick up my lab notebook or read my Lab Report in a few months, I can still explain to myself or others exactly what I did? Lab Notes generally include these components: Title: Match the title to the title stated in the lab manual. Purpose: Write a brief statement about what the experiment is designed to determine or demonstrate.

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Procedure: Briefly summarize what you did to perform this experiment and what equipment you used. Do not simply copy the procedure statement from the lab manual. Data Tables: Always prepare tables before experimenting, so they will be ready to receive data as it is accumulated. Tables are an excellent way to organize your observational data, and where applicable, the Procedure section advises a table format for data recording. Observations: Record what you observed, smelled, heard, or otherwise measured? Generally, observations are most easily recorded in table form. Questions: Thoughtfully answer the questions asked throughout and at the end of experiments. The questions are designed to help you think critically about the experiment you just performed. Conclusions: What did you learn from the experiment? Base your conclusions on your observations during the experiment. Write your conclusions in your best, formal English, using complete sentences, full paragraphs, and correct spelling. Some general rules for keeping a lab notebook are:  Leave the first two to four pages blank so you can add a Table of Contents later. Entries in the Table of Contents should include the experiment number, name, and page number.  Neatly write your records without being fussy.  Do not provide a complete Lab Report in your lab notebook. Instead, record what you did, how you did it, and what your results were. Your records need to be substantial enough that any knowledgeable person familiar with the subject of your experiment can read the entries, understand exactly what you did, and repeat your experiment if necessary.  Organize all numerical readings and measurements in appropriate data tables. Refer to the sample Lab Report in this lab manual.  Always identify the units (e.g., centimeters, kilograms, or seconds) for each set of data you record.  Always identify the equipment you are using so you can refer to it later if you need to recheck your work.  Capture the important steps and observations of your experiments using digital photos in which you are pictured. Photos within your Lab Report document both what you observed and that you actually performed the experiment.

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 Record more rather than less data. Even details that may seem to have little bearing on your experiment (e.g., time and temperature variances when the data were taken) may turn out to have great bearing on your future results analysis.  Make a note if you suspect that a particular data set may not be reliable.  Never erase data. If you think an entry in your notes is in error, draw a single line through it and note the correction, but don’t erase or scratch it out completely. You may later find that the information is significant after all. Errors: Although experimental results may be in considerable error, there is never a wrong result in an experiment. Whatever happens in nature, including the laboratory, cannot be wrong. If you made your observations and measurements carefully, your results will be correct. Errors may have nothing to do with your investigation, or they may be mixed up with so many other unexpected events that your report is not useful. Even errors and mistakes have merit and often lead to our greatest learning experiences. Errors provide important results to consider; thus, you must think carefully about the interpretation of all your results, including your errors. Experiment Completion: The cardinal rule in a laboratory is to fully carry out all phases of your experiments instead of “dry-labbing” or taking shortcuts. The Greek scientist, Archytas, summed this up very well in 380 B.C.:

Lab Reports
This lab manual covers the overall format that formal Lab Reports generally follow. Remember, the Lab Report should be self-contained, so anyone, including someone without a science background or lab manual, can read it, understand what was done, and understand what was learned. Data and calculation tables have been provided for many of the experiments in this lab manual, and you are encouraged to use them. Computer spreadsheet programs such as Microsoft® Excel® and websites like nces.ed.gov/nceskids/Graphing/Classic/line.asp can also greatly facilitate the preparation of data tables and graphs. Visit www.ncsu.edu/labwriter/ for additional information on preparing Lab Reports.

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Lab Reports are expected to be word processed and to look organized and professional. They should be free of grammar, syntax, and spelling errors and be a respectable presentation of your work. Avoid writing in the first person as much as possible. Lab Reports should generally contain and clearly distinguish the sections discussed in detail below. The presentation and organization skills you’ll develop by producing science Lab Reports is beneficial to all potential career fields. Lab Report Format: Title Page This is the first page of the Lab Report and consists of: a. Experiment number and/or title b. Your name c. Names of lab partner(s) d. Date and time experiment was performed e. Location if work was performed in the field f. Course number Section 1: Abstract, Experiment, and Observation Abstract: Even though the abstract appears at the beginning of the Lab Report, you will write it last. An abstract is a very concise description of the experiment’s objectives, results, and conclusions and should be no longer than a paragraph. Experiment and Observation: In chronological order, carefully and concisely describe what was done, what was observed, and what, if any, problems were encountered. Describe what field and laboratory techniques and equipment you used to collect and analyze the data on which the conclusions are based. Insert photos and graphic illustrations in this section; graphics should be in .jpg or .gif format to minimize electronic file size. Show all your work for any calculations performed. Title every graph and clearly label the axes. Data point connections should be “best-fit curves,” which are smooth, straight or curved lines that best represent the data, instead of dot-to-dot data point connections. Include all data tables, photos, graphs, lists, sketches, etc. in an organized fashion. Include relevant symbols and units with data. Generally one or two sentences explaining how data was obtained is appropriate for each data table. Note any anomalies observed or difficulties encountered in collecting data as these may affect the final results. Include information about any errors you observed and what you learned from them. Be deliberate in recording your experimental procedures in detail. Your comments may also include any preliminary ideas you have for explaining the data or trends you see emerging.

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Section 2: Analysis – Calculations, Graphs, and Error Analysis Generally, the questions at the end of each experiment will act as a guide when preparing your results and conclusions. The analysis is written in paragraph form and no more than one or two pages long. As you write, consider the following: a. What is the connection between the experimental measurements taken and the final results and conclusions? How do your results relate to the real world? b. What were the results of observations and calculations? c. What trends were noticed? d. What is the theory or model behind the experiment? e. Do the experimental results substantiate or refute the theory? Why? Be sure to refer specifically to the results you obtained. f. Were the results consistent with your original predictions of outcomes or were you forced to revise your thinking? g. Did errors (e.g., environmental changes or unplanned friction) occur? If so, how did these errors affect the experiment? h. Did any errors occur due to the equipment used (e.g., skewed estimates due to a lack of sufficient measurement gradients on a beaker)? i. What recommendations might improve the procedures and results?

Error Analysis: In a single paragraph, comment on the accuracy and precision of the apparatuses used, include a discussion of the experimental errors, and include an estimate of the errors in your final result. Remember, errors are not mistakes. Errors arise because the apparatus and/or the environment inevitably fail to match the ideal circumstances assumed when deriving a theory or equation. The two principal sources of error are: Physical phenomena: Elements in the environment may be similar to the phenomena being measured and may affect the measured quantity. Examples include stray magnetic or electric fields or unaccounted for friction. Limitations of the observer, analysis, and/or instruments: Examples include parallax error when reading a meter tape, the coarse scale of a graph, and the sensitivity of the instruments. Human errors and mistakes that are not acceptable scientific errors include: calculator misuse (e.g., pushing the wrong button, misreading the display); misuse of equipment; faulty equipment; incorrectly assembled circuits or apparatuses.

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Section 3: Discussion, Results, and Conclusions Discussion: Carefully organize your discussion to include consideration of the experiment’s results, interpretation of the results, and uncertainty in the results. This section is written in paragraph form and is generally no more than one to two pages in length. Occasionally it will be more appropriate to organize various aspects of the discussion differently. While not all of the following questions will apply to every experiment, consider them when writing your Lab Report. Results: a. What is the connection among your observations, measurements, and final results? b. What were the independent or dependent variables in the experiment? c. What were the results of your calculations? d. What trends were noticeable? e. How did the independent variables affect the dependent variables? For example, did an increase in a given independent variable result in an increase or decrease in the associated dependent variable? Interpretation of Results: a. What is the theory or model behind the experiment you performed? b. Do your experimental results substantiate or agree with the theory? Why or why not? Be sure to refer specifically to your experimental results. c. Were these results consistent with your original beliefs or were you forced to reevaluate your prior conceptions? Uncertainty in results: a. How much did your results deviate from expected values? b. Are the deviations due to error or uncertainty in the experimental method? Can you think of ways to decrease the amount of uncertainty? c. Are the deviations due to idealizations inherent in the theory? What factors has the theory neglected to consider? d. In either case, consider whether your results display systematic or random deviations.

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Lab Notes and Lab Reports undoubtedly sound complex and overwhelming at first, but don’t worry. They will make more sense to you when you begin performing the experiments and writing reports. After writing your first few Lab Reports, the reports will become second nature to you. Refer to the sample Lab Report in this manual.

Laboratory Drawings
Laboratory work often requires you to illustrate findings in representational drawings. Clear, well organized drawings are an excellent way to convey observations and are often more easily understood than long textual descriptions. The adage “a picture is worth a thousand words” really is true when referring to Lab Notes. Give yourself ample drawing space and leave a white margin around the actual illustration so it is clearly visible. Also leave a broad margin along one side of your drawing to insert object labels. Use a ruler to draw straight lines for the labels and connecting lines to the corresponding objects. The image below provides an example of how laboratory drawings should look when they are included in a formal Lab Report. Students often believe they can’t draw; however, with a little practice, anyone can illustrate laboratory observations. A trick many artists use is to form a mental grid over the scene and draw within the grid. For example, quickly make a free hand drawing of the diagram below. Now, mentally divide the diagram into quarters and try drawing the diagram again. In all likelihood, the second, grid-based drawing yielded a better result.
SOURCE OF DRAWING
Such as MUNG BEAN

Your Name Date of Drawing

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Visual Presentation of Data
Like pictures, good graphs and tables can quickly and clearly communicate information visually; hence, graphs and tables are often used to represent or depict collected data. Graphs and tables should be constructed to stand alone – all the information required to understand a graph or table should be included. Tables A table presents data clearly and logically. Independent data is listed in the left column and all dependent data is listed to the right. While there will be only one independent variable, there can be more than one dependent variable. The decision to present data in a table rather than a graph is often arbitrary; however, a table may be more appropriate when the data set is too small to warrant a graph or is large, complex, and not easily illustrated. Often, data tables display raw data, and a graph provides visualization of the data. Graphs A graph is composed of two basic elements: the graph itself and the graph legend. The legend provides the descriptive information needed to fully understand the graph. In the graph at right, the legend shows that the red line represents Red Delicious apples, the brown line represents Gala apples, and the green line represents Wine Sap apples. Without the legend it would be difficult to interpret this graph. Trend line or Line of best fit: To more clearly show the trend between two sets of data, ”lines of best fit” or ”trend lines” are added to data. This enables us to determine the general trend of the data or to better use the data for predictive purposes. Excel or a similar spreadsheet program can easily add a trend line to the data. Use Excel to make a scatter plot of the data and then add a trend line. In most cases the line may not pass through very many of the plotted points. Instead, the idea is to get a line that has equal numbers of points on either side. Most people start by viewing the data to see which trend
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Plant Height versus Fertilizer Solution X-Axis Y-Axis Fertilizer % Plant Height in cm solution 0 25 10 34 20 44 30 76 40 79 50 65 60 40

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line fits the data the best (i.e. which kind of trend line comes closest to the points). For most (but not all) of the data a linear trend line will provide a good fit. Trendlines are most useful to predict data that is not measured. In interpolation, the trend line is used to construct new data points within the range of a discrete set of known data points. Similarly, a trend line can be used to extrapolate data that are outside of the measured data set. This is illustrated in Figures 1 through 4. Sample data set: Time, t (seconds) Distance, x (cm)

0.1 3.8 0.3 6.1 0.5 7.95 0.8 11 Figure 1: Sample data

Figure 2: Scatter graph of sample data

Figure 3: Scatter graph with a trendline and the equation of the line.

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Figure 4: Interpolation of a data point As an example of interpolation, if we want to know the cm-displacement at a time of 0.6 s on the Figure 4 Interpolation of data point, we add a vertical line from 0.6 s to the trendline, and then a horizontal line to the distance. This will reads an approximately distance of 9 cm. More accurately, the slope equation of the line may be used to calculate this value: y=10.182 x + 2.885; y = 10.182*0.6+2.885 = 8.99 cm To extrapolate, we would extend the trendline beyond the collected data and repeat the above process. We could also use the slope equation of the line. For example, using the equation to extrapolate the distance at 1 sec. : y = 10.182*1.0+2.885 = 13.1 cm Graph Setup: Consider a simple plot of the Plant Height versus Plant Fertilizer Concentration as shown in one of the data tables above. This is a plot of points on a set of X and Y coordinates. The X-axis or abscissa runs horizontally; the Y-axis or ordinate runs vertically. By convention, the X-axis is used for the independent variable – a manipulated variable in an experiment whose presence determines the change in the dependent variable. The Y-axis is used for the dependent variable – the variable affected by another variable or by a certain event. In this example, the amount of fertilizer is the independent variable and goes on the X-axis. The plant height, since it may change depending on changes in fertilizer amount, goes on the Y-axis. One way to determine which data goes on the X-axis versus the Y-axis

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is to think about what affects what. Does fertilizer affect plant height or does plant height affect fertilizer. Only one of these options should make sense. Plant height will not change the fertilizer, but the fertilizer will affect the plant height. The variable that causes the change is independent, and the variable that changes is dependent. If the data deals with more than one dependent variable, it would be represented with three lines and a key or legend would identify which line represents which data set. In all graphs, each axis is labeled, and the units of measurement are specified. When a graph is presented in a Lab Report, the variables, the scale, and the range of the measurements should be clear. Refer to the table below when setting up a line graph. How to Construct a Line Graph Step 1 Identify the variables. Explanation  Independent variable: Controlled by the experimenter. - Goes on the X-axis – the abscissa. - Located on the left side of a data chart.  Dependent variable: Changes with the independent variable. - Goes on the Y-axis – the ordinate. - Located on the right side of a data table  Subtract the lowest data value from the highest. - Calculate each variable separately.  Choose a scale that best fits each variable’s range (e.g., increments of one, two, five, etc.). - Choose a scale that spreads the graph over most of the available space.  The axes tell what the graph’s data lines represent. - Always include units of measure (e.g., days, time, meters, etc.).  Plot each data value on the graph with a dot. - Add the numerical data next to the dot, if there is room and you avoid cluttering the graph.  Draw a straight or curved line that best fits the data points. - Most graphs are shown as smooth lines, not dotby-dot connections.  The title should clearly tell what the graph is depicting.  Provide a legend to identify different lines, if the graph has more than one set of data.

2 Determine the range. 3 Determine the scale. 4 Number and label each axis. 5 Plot the data points. 6 Draw the graph.

7 Title the graph.

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Computer Graphing Using MS Excel
These instructions apply to the 2003 version of Excel. If you have a newer version, perform an Internet search for current instructions. This set of general instructions will be used to plot the following data: Time, t (seconds) 0 .1 .2 .3 .4 .5 Distance, x (cm) 0 9.8 30.2 59.9 99.2 148.9

When graphing x-y data, you must first determine which variable will be the X-variable and which will be the Y-variable. If you are unsure, review the previous Visual Presentation of Data section. Create a File a. Open a blank Excel spreadsheet. b. Save the file under an appropriate name, such as Exercise 1-Time vs Distance. Create Data Table 1. Enter the X-data points in the first column (A). 2. Enter the Y-data points in the second column (B). Note: It is often useful to enter zero as the first data value, but not always. Nonetheless, it is a good habit to start. 3. Highlight all the data values by placing the curser in the first cell to be highlighted (A1) and either:   Clicking and holding the left mouse button while pulling the mouse and curser down and to the right so the cells are highlighted and then releasing the button. Holding the key on the keyboard and using the direction arrows to move the cursor over the desired area until all cells are highlighted.

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Create Graph 4. Click the Chart Wizard icon on the toolbar or select Chart from the Insert menu.

Step 1: Chart Type 5. Select XY (Scatter) from the Standard Types tab. 6. Select your preferred Chart sub-type. Although you can choose graphs with data points, graphs with smooth lines are preferable. 7. Click Next >.

Step 2: Chart Source Data Carefully review this information to ensure the graph has the correct values for the vertical and the horizontal axes. 8. Select the Columns option button on the Data Range tab. The range should read =Sheet1!$A$2:$B$7 This means the data:  Comes from Sheet 1 of the workbook.  Comes from cells A2 through B7.  Has been organized by data columns instead of data rows.

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9. Under the Series tab, the values for the Xand Y-axes are as follows: X Values: =Sheet1!$A$2:$A$7 Y Values: =Sheet1!$B$2:$B$7 This means:  The data comes from Sheet 1 of the workbook.  The X-value data comes from cells A2 through A7.  The Y-value data comes from cells B2 through B7.

Note: If the data is reversed, replace the incorrect column letters and numbers with the correct ones. 10. To maintain the appropriate reference, rename the series of data points from the default, Series1, by entering another name in the Name field. Data is commonly used. 11. Click Next >. Step 3: Chart Options 12. Chart Options allows you to assign titles and labels to your graph as well as determine the appearance of gridlines and legends. Make your selections. 13. Click Next >. Step 4: Chart Location 14. Choose the location where your graph will be created.   As new sheet: Opens a new page on which the graph will appear. As object in: Places the graph in the current spreadsheet.

If you’re unsure, select As object in so the data and graph will appear on the same page.

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15. Click Finish to complete the graph.

Using Excel® To Calculate the Slope of the Line 1. Put your cursor on the line in your graph and right-click. An option menu will drop down; select “Add Trendline.” 2. Left-click on “Add Trendline.” The window to the right will appear with icons for the types of trend lines possible. 3. For most data you will usually want a “Linear” trendline. However, from your math classes you should recognize that the curve in your final graph (previous page) resembles a parabola which represents a quadratic or 2nd order polynomial equation. Thus, among the trendline options you will click on the polynomial option. 4. Note that a trendline has now been added to your graph as seen in the top graph of the double graph at right. If you accidentally clicked on linear trendline, the trendline would look like the bottom graph. You can see that the linear trendline does not fit as well polynomial one.

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5. Now, put your cursor on the trendline itself and right-click; then left-click on the “Format Trendline” option that appears. 6. In the box that then appears, select the “Options” tab in the Format Trendline box. Then check:  "Set intercept = 0", and  “Display equation on chart”. 7. Click OK and the new graph below appears with the equation for the trendline shown on it in the form y=mx+ b. You should recognize that m = slope. (Caveat: Only click on “select intercept = 0” when the line goes through zero.)

SHORTCUT: You can select the type and formatting of a trendline in one step. From Step 3 after selecting the polynomial option, go straight to the Options tab where you can immediately check “Set intercept = 0 “and “Display equation on chart”. Click OK and you are done. Delete your graph and start over to practice and feel comfortable with all the above graphing steps and this shortcut.

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Using Excel® for Calculations Many times in physics and scientific or engineering work, one must repeat the same basic calculations using different sets of numbers. As an example consider trying to find the average speed between the distances in our earlier table. The first calculation would look like … Time (seconds) Distance (cm) 0 0 .1 9.8 .2 30.2 .3 59.9 Vavg = ∆x = 9.8 cm – 0.0 cm = 98 cm/s .4 99.2 ∆t 0.1 – 0.0 s .5 148.9 The second calculation would be Vavg = ∆x = 30.2 cm – 9.8 cm = 204 cm/s ∆t 0.2 – 0.1 s There are only five calculations to compute here and doing all five on a calculator is not a lot of work. However, if there were 100 or 1000 such calculations, it would be extremely laborious! Fortunately Excel® can do these calculations easily and quickly with formulas plus copy and paste functions. Let’s try it with the above data. First, enter the time and distance data into Excel®. Start by inputting the zero values in “cells” A1 and B1 and then enter the rest of the data in the A and B “columns.” (Hint: you may wish to begin inputting your data in “row” 5 or so in the future in order to leave space above the data to later include a spreadsheet title or other information.) Observe that the first non-zero data is in row 2 and in cells A2 and B2. In addition, our time data [t] is in column A and our distance data [x] is in column B. Next, think about how you might construct a formula for our problem. If ∆x, the change in distance can be computed as B2-B1, and ∆t, the change in time can be computed as A2-A1, then we could use this formula for the change in distance over the change in time: = (B2-B1)/(A2-A1) This formula is a math statement that says the difference of the values in boxes B3 and B2 should be divided by the difference of the values in boxes A3 and A2. In order to record in column C the average speed between the distances for all of the sets of data, you must first input the formula above into cell C2 and then copy and paste it into the remaining cells. To do this: 1. Place your curser in the cell C2

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2. Insert an equal sign [=] to alert Excel® this will be a formula rather than data. 3. Type your = (B2-B1)/(A2-A1) formula using no extra spaces between numbers and operative signs and hit enter. Observe that your formula appears in the fx box above the columns as it is entered. Refer to this box to make sure your formula is typed correctly. 4. If your formula was correctly input Excel® will do the calculation for you and a value of 98 should appear in C2. You can now use the same formula for each of the successive sets of values and simplify the process by using the copy and paste functions. When you copy a formula from one Excel® cell and then paste it in another cell, Excel® automatically adjusts the formula to correspond to the cursors’ new position. To copy and paste data from a cell, move your cursor to that cell and either use:  Your mouse: right click to display options and click copy or paste  Edit command at the top of your screen: select the copy or paste option and left click the mouse or hit enter on the keyboard.  Keyboard commands: use Control + C for copy and Control + V for paste 5. Move your cursor to cell C2 and “copy” its contents in one of the ways described above. When the cell appears to vibrate, its contents can be copied into other cells. Now move the cursor to 3C and “paste” it in one of the ways described above. To stop the source cell vibrations and end the possibility of copying its data further, hit enter or escape. Note that the formula for cell C3 now correctly reads =(B3-B2)/(A3-A2) and corresponds to the data in row 3. 6. To transfer the formula into multiple cells at the same time, copy the formula in cell C2, highlight cells C3 through C6, and paste. Note that the formula adjusts itself for each row of data and Excel® will properly calculate the average velocity for each of the additional sets of data; the answers are now shown in column C. Reinforcing Exercise: For the set of data values located on the next page, find the average acceleration between each of the speeds using Excel®.

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Time (sec) 0.0906 0.1361 0.1714 0.201 0.2267 0.2281 0.2511 0.262 0.2916 0.3075 0.3187 0.3371 0.3417 0.3642 0.3723 0.3872 0.3994 0.4224 0.452

Speed (cm/s) 138 184 219 249 275 274 299 310 340 355 364 386 390 408 422 435 441 471 499

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SAFETY CONCERNS
You, as a responsible science student and researcher, are solely responsible for safely storing and using your LabPaq materials and for conducting your experiments in a safe and responsible manner. Items in your LabPaq can be especially dangerous to children and pets, so the LabPaq should always be kept safely stored out of their reach. The LabPaq may contain acids or other chemicals that can cause burns if mishandled plus serious illness and or death if consumed. Many LabPaq items are made of glass and/or have sharp edges that pose potential risks for cuts and scratches. While LabPaq thermometers do not contain mercury, they might still break and cause injury. LabPaqs contain small items and materials that could cause choking, injury, or death if misused. Experimentation may require you to climb, push, pull, spin, and whirl. While these activities are not necessarily dangerous, they can pose hazards, and you should always undertake these activities cautiously and with consideration for your surroundings. If you need to climb to take measurements, make sure any stool, chair, or ladder you use is sturdy and take ample precautions to prevent falls. It is wise to have a partner help keep you stable when you must climb. Be especially aware of experimental equipment that you must put in motion, and act cautiously to ensure that items cannot go astray and cause injury to people or property. If you or anyone accidentally consumes or otherwise comes into contact with a substance that could be toxic or cannot be easily washed away, immediately call:

The National Poison Control Center: 1-800-222-1222

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Your eyesight is precious and should be protected against chemical spills or splashes as well as flying objects and debris. Always wear safety goggles when working with chemicals of any kind and when working with non-chemical objects that could possibly fly into your eyes. Since chemicals, dirt, and germs are often involved in laboratory experiments, you should never eat or smoke in your laboratory area. Protect your body by keeping your hair tied back from your face and by wearing old clothing that fully covers your arms and legs. You also need to protect your home furnishings from damage during your experimentation. Cover your work surface with plastic or paper towels when appropriate to prevent ruining furniture and to aid in cleanup. The best safety tools you have are your own mind and intellectual ability to think and plan. After previewing each experiment, carefully think about what safety precautions you need to take to experiment safely, and then take them! Since it is impossible to control students’ use of this lab manual and related LabPaqs or students’ work environments, the author(s) of this lab manual, the instructors and institutions that adopt it, and Hands-On Labs, Inc. – the publisher of the lab manual and the producer of LabPaqs – authorize the use of these educational products only on the express condition that the purchasers and users accept full and complete responsibility for all and any liability related to their use of same. Additional terms authorizing the use of a LabPaq are contained in its Purchase Agreement available at www.LabPaq.com.

Basic Safety Guidelines
This section contains vital information that you must thoroughly read and completely understand before beginning to perform experiments. Science experimentation is fun but involves potential hazards which you must acknowledge to avoid. To safely conduct science experiments, you must learn and follow basic safety procedures. While there may be fewer safety hazards for physics and geology experimentation than chemistry and biology, safety risks exist in all science experimentation and should be taken very seriously. Thus, the following safety procedures review is relevant to all students regardless of their field of study While this lab manual tries to include all relevant safety issues, not every potential danger can be foreseen, as each experiment involves different safety considerations. You must always act responsibly, learn to recognize potential dangers, and always take appropriate precautions. Regardless of whether you will be working in a campus or home laboratory setting, it is extremely important that you know how to anticipate and avoid possible hazards and to be safety conscious at all times.

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Basic Safety Procedures Science experimentation often involves using toxic chemicals, flammable substances, breakable items, and other potentially dangerous materials and equipment. All of these things can cause injury and even death if not properly handled. These basic safety procedures apply when working in a campus or home laboratory.  Because eyesight is precious and eyes are vulnerable to chemical spills and splashes, shattered rocks and glass, and floating and flying objects: - Always wear eye protecting safety goggles when experimenting. Because toxic chemicals and foreign matter may enter the body through digestion: - Never drink or eat in laboratory areas. - Always wash your hands before leaving the laboratory. - Always clean the laboratory area after experimentation. Because toxic substances may enter the body through the skin and lungs: - Ensure the laboratory always has adequate ventilation. - Never directly inhale chemicals. - Wear long-sleeved shirts, pants, and enclosed shoes when in the laboratory. - Wear gloves and aprons when appropriate. Because hair, clothing, and jewelry can create hazards, cause spills, and catch fire while experimenting: - Always tie or pin back long hair. - Always wear snug fitting and preferably old clothing. - Never wear dangling jewelry or objects. Because a laboratory area contains various fire hazards: - Smoking is always forbidden in laboratory areas. Because chemical experimentation involves numerous potential hazards: - Know how to locate and use basic safety equipment. - Never leave a burning flame or reaction unattended. - Specifically follow all safety instructions. - Never perform any unauthorized experiments. - Always properly store equipment and supplies. Because science equipment and supplies often include breakable glass and sharp items posing potential risks for cuts and scratches; and small items and dangerous chemicals potentially causing death or injury if consumed: - Carefully handle all science equipment and supplies. - Keep science equipment and supplies stored out of the reach of pets and small children. - Ensure pets and small children will not enter the lab area while experimenting.

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Because science experimentation may require students to climb, push, pull, spin, and whirl: - Undertake these activities cautiously and with consideration for the people, property, and objects that could be impacted. - Ensure stools, chairs, or ladders used to climb are sturdy and take ample precautions to prevent falls. Because your best safety tools are your own mind and intellectual ability: - Always preview each experiment, carefully think about what safety precautions need to be taken to experiment safely, and then take them.

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Basic Safety Equipment: You can find the following pieces of basic safety equipment in all campus laboratories. Informal and home laboratories may not have all of these items, but you can usually make simple substitutions. You should know the exact location and proper use of these items. Eyewash Station: All laboratories should have safety equipment to wash chemicals from the eyes. A formal eyewash station looks like a water fountain with two faucets directed up at spaces to match the space between the eyes. In case of an accident, the victim's head is placed between the faucets while the eyelids are held open, so the faucets can flush water into the eye sockets and wash away the chemicals. In an informal laboratory, you can substitute a hand-held shower wand for an eyewash station. After the eyes are thoroughly washed, consult a physician promptly. Fire Blanket: A fire blanket is a tightly woven fabric used to smother and extinguish a fire. It can cover a fire area or be wrapped around a victim who has caught on fire.

Fire Extinguisher: There are several types of fire extinguishers, but at least one should be available in all laboratories. You should familiarize yourself with and know how to use the particular fire extinguisher in your laboratory. At a minimum, home laboratories should have a bucket of water and a large container of sand or dirt to smother fires.

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First-Aid Kit: This kit of basic first-aid supplies is used for the emergency treatment of injuries and should be standard in both formal and informal laboratories. It should always be well stocked and easily accessible.

Fume Hood: A fume hood is a hooded area containing an exhaust fan that expels noxious fumes from the laboratory. Experiments that might produce dangerous or unpleasant vapors are conducted under this hood. In an informal laboratory such experiments should be conducted only with ample ventilation and near open windows or doors. If a kitchen is used for a home laboratory, the exhaust fan above the stove substitutes nicely for a fume hood. Safety Shower: This shower is used in formal laboratories to put out fires or douse people who have caught on fire or suffered a large chemical spill. A hand-held shower wand is the best substitute for a safety shower in a home laboratory.

Safety Goggles: There is no substitute for this important piece of safety equipment! Spills and splashes do occur, and eyes can very easily be damaged if they come in contact with laboratory chemicals, shattered glass, swinging objects, or flying rock chips. While normal eyeglasses provide some protection, objects can still enter the eyes from the side. Safety goggles cup around all sides of the eyes to provide the most protection and can be worn over normal eyeglasses when necessary. Spill Containment Kit: This kit consists of absorbent material that can be ringed around a spilled chemical to keep the spill contained until it can be neutralized. The kit may simply be a container full of sand or other absorbent material such as cat litter.

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Potential Laboratory Hazards: Recognizing and respecting potential hazards is the first step toward preventing accidents. Please appreciate the grave dangers the following laboratory hazards represent. Work to avoid these dangers and consider how to respond properly in the event of an accident. Acid Splatter: When water is added to concentrated acid, the solution becomes very hot and may splatter acid. Splattering is less likely to occur if you add acid slowly to the water. Remember this AAA rule: Always Add Acid to water, never add water to acid. Chemical Ingestion: Virtually all chemicals found in a laboratory are potentially toxic. To avoid ingesting dangerous chemicals, never taste, eat, or drink anything while in the laboratory. All laboratories, and especially those in home kitchens, should always be thoroughly cleaned after experimentation to avoid this hazard. In the event of any chemical ingestion, immediately consult a physician. Chemical Spills: Flesh burns may result if acids, bases, or other caustic chemicals are spilled and come in contact with skin. Flush the exposed skin with a gentle flow of water for several minutes at a sink or safety shower. Neutralize acid spills with sodium bicarbonate – simple baking soda. If eye contact is involved, use the eyewash station or its substitute. Use the spill containment kit until the spill is neutralized. To better protect the body from chemical spills, wear long-sleeved shirts, full-length pants, and enclosed shoes when in the laboratory. Fires: The open flame of a Bunsen burner or any heating source, combined with inattention, may result in a loose sleeve, loose hair, or some unnoticed item catching fire. Except for water, most solvents, including toluene, alcohols, acetones, ethers, and acetates, are highly flammable and should never be used near an open flame. As a general rule, never leave an open flame or reaction unattended. In case of fire, use a fire extinguisher, fire blanket, and/or safety shower. Fume Inhalation: To avoid inhaling dangerous fumes, partially fill your lungs with air and, while standing slightly back from the fumes, use your hand to waft the odors gently toward your nose. Lightly sniff the fumes in a controlled fashion. Never inhale fumes directly! Treat inhalation problems with fresh air, and consult a physician if the problem appears serious. Glass Tubing Hazards: Never force a piece of glass tubing into a stopper hole. The glass may snap, and the jagged edges can cause serious cuts. Before inserting glass tubing into a rubber or cork stopper hole, be sure the hole is the proper size. Lubricate the end of the glass tubing with glycerol or soap, and then, while grasping the tubing with a heavy glove or towel, gently but firmly twist it into the hole. Treat any cuts with appropriate first aid. Heated Test Tube Splatter: Splattering and eruptions can occur when solutions are heated in a test tube. You should never point a heated test tube towards anyone. To minimize this danger, direct the flame toward the top rather than the bottom of the test tube. Gently agitate the tube over the flame to heat the contents evenly.

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Horseplay: A laboratory full of potentially dangerous chemicals and equipment is a place for serious work, not for horseplay! Fooling around in the laboratory is an invitation for an accident. Shattered Glassware: Graduated cylinders, volumetric flasks, and certain other pieces of glassware are not designed to be heated. If heated, glassware is likely to shatter and cause injuries. Always ensure you are using heatproof glass before applying it to a heat source. Take special caution when working with any type of laboratory glassware CAUTION for Women: If you are pregnant or could be pregnant, you should seek advice from your personal physician before doing any type of science experimentation.

Material Safety Data Sheets
An important skill in the safe use of chemicals is the ability to read a Material Safety Data Sheet (MSDS). An MSDS is designed to provide chemical, physical, health, and safety information on chemical reagents and supplies. It provides information about how to handle, store, transport, use and dispose of chemicals in a safe manner. An MSDS also provides workers and emergency personnel with the proper procedures for handling and working with chemical substances. While there is no standard format for an MSDS, any MSDS provides basic information about physical data, toxicity, health effects, first-aid procedures, chemical reactivity, safe storage, safe disposal, required protective equipment, and spill cleanup procedures. An MSDS is required to be readily available at any business where any type of chemical is used. Even daycare centers and grocery stores need MSDSs for their cleaning supplies. It is important to know how to read and understand an MSDS. An MSDS is generally organized into the following sections: Section 1: Product Identification Chemical name and trade names Section 2: Hazardous Ingredients Components and percentages Section 3: Physical Data Boiling point, density, solubility in water, appearance, color, etc. Section 4: Fire and Explosion Data Flash point, extinguisher media, special fire fighting procedures, and unusual fire and explosion hazards Section 5: Health Hazard Data Exposure limits, effects of overexposure, emergency and first-aid procedures
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Section 6: Reactivity Data Stability, conditions to avoid, incompatible materials, etc. Section 7: Spill or Leak Procedures Steps to take to control and clean up spills and leaks and waste disposal methods Section 8: Control Measures Respiratory protection, ventilation, protection for eyes or skin, or other needed protective equipment Section 9: Special Precautions How to handle and store, steps to take in a spill, disposal methods, and other precautions The MSDS is a tool available to employers and workers for making decisions about chemicals. The least hazardous chemical should be selected for use whenever possible, and procedures for storing, using, and disposing of chemicals should be written and communicated to workers. View MSDS information at www.hazard.com/msds/index.php. You can also find a link to MSDS information at www.LabPaq.com. If there is ever a problem or question about the proper handling of any chemical, seek information from one of these sources.

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Safety Quiz
Refer to the illustration on the following page when answering the questions. 1. List three (3) unsafe activities in the illustration and explain why each is unsafe.

2. List three (3) correct procedures depicted in the illustration.

3. What should Tarik do after the accident?

4. What should Lindsey have done to avoid an accident?

5. Compare Ming and David's laboratory techniques. Who is following the rules?

6. What are three (3) things shown in the laboratory that should not be there?

7. Compare Joe and Tyler's laboratory techniques. Who is working the correct way?

8. What will happen to Ray and Chris when the instructor catches them?

9. List three (3) items in the illustration that are there for the safety of the students.

10. What is Consuela doing wrong?

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Science Lab Safety Reinforcement Agreement
Any type of science experimentation involves potential hazards, and unforeseen risks may exist. The need to prevent injuries and accidents cannot be overemphasized! Use of this lab manual and any LabPaqs are expressly conditioned upon your agreement to follow all safety precautions and accept full responsibility for your actions. Study the safety section of this lab manual until you can honestly state the following:  Before beginning an experiment I will first read all directions and then assemble and organize all required equipment and supplies.  I will select a work area that is inaccessible to children and pets while experiments are in progress. I will not leave experiments unattended, and I will not leave my work area while a chemical equipment is set up unless the room is locked.  To avoid the potential for accidents, I will clear my home laboratory workspace of all non-laboratory items before setting up equipment and supplies for my experiments.  I will never attempt an experiment until I fully understand it. If in doubt about any part of an experiment, I will first speak with my instructor before proceeding.  I will wear safety goggles when working with chemicals or items that can get in my eyes  I know that except for water, most solvents, such as toluene, alcohols, acetone, ethers, and ethyl acetate are highly flammable and should never be used near an open flame.  I know that the heat created when water is added to concentrated acids is sufficient to cause spattering. When preparing dilute acid solutions, I will always add the acid to the water – rather than the water to the acid – while slowly stirring the mixture.  I know it is wise to wear rubber gloves and goggles when handling acids and other dangerous chemicals; I should neutralize acid spills with sodium bicarbonate; and I should wash acid spilled on skin or clothes immediately with plenty of cold water.  I know that many chemicals produce toxic fumes, and cautious procedures should be used when smelling any chemical. When I wish to smell a chemical, I will never hold it directly under my nose, but will use my hand to waft vapors toward my nose.  I will always handle glassware with respect and promptly replace any defective glassware. Even a small crack can cause glass to break, especially when heated. To avoid cuts and injuries, I will immediately dispose of any broken glassware.

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 I will avoid burns by testing glass and metal objects for heat before handling. I know that the preferred first aid for burns is to immediately hold the burned area under cold water for several minutes.  I know that serious accidents can occur when wrong chemicals are used in an experiment. I will always read labels before removing chemicals from their containers.  I will avoid the possibility of contamination and accidents by never returning an unused chemical to its original container. To avoid waste I will try to pour only the approximate amount of chemicals required.  I know to immediately flush any chemical spill on the skin with cold water and consult a doctor if required.  To protect myself from potential hazards, I will wear long pants, a long-sleeved shirt, and enclosed shoes when performing experiments. I will tie up any loose hair, clothing, or other materials as well.  I will never eat, drink, or smoke while performing experiments.  After completing all experiments I will clean my work area, wash my hands, and store the laboratory equipment in a safe place inaccessible to children and pets.  I will always conscientiously work in a reasonable and prudent manner to optimize my safety and the safety of others whenever and wherever I am involved with any type of science equipment or experimentation. It is impossible to control students’ use of this lab manual and related LabPaqs or students’ work environments. The author(s) of this lab manual, the instructors and institutions that adopt it, and Hands-On Labs, Inc. – the publisher of the lab manual and producer of LabPaqs – authorize the use of these educational products only on the express condition that the purchasers and users accept full and complete responsibility for all and any liability related to their use of same. Please review this document several times until you are certain you understand it and will fully abide by its terms. Then sign and date the agreement were indicated. I am a responsible adult who has read, understands, and agrees to fully abide by all safety precautions prescribed in this lab manual for laboratory work and for the use of a LabPaq. Accordingly, I recognize the inherent hazards associated with science experimentation; I will always experiment in a safe and prudent manner; and I unconditionally accept full and complete responsibility for any and all liability related to my purchase and/or use of a science LabPaq or any other science products or materials provided by Hands-On Labs, Inc. (HOL). ____________________________________________________ Student’s Name (print) and Signature ____________ Date

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EXPERIMENTS

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Using the Microscope
Laszlo Vass, Ed.D. Version 09.1.02

Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will have the opportunity to explore the different parts of a microscope and its associated functions. They will learn how to care for and use a microscope, as well as the proper techniques for focusing slides.

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Objectives
The student will have the opportunity to:  Identify the parts of a microscope and list the functions of each part.  Demonstrate the proper care and use of the microscope.  Demonstrate the proper techniques for focusing a slide. Time Allocation: 1.5 hours

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Materials
Materials Student provides LabPaq provides Label or Box/Bag Slide Box AP-1 Qty 1 1 Item Description Microscope and all of its lenses & electric light source Slide - Hyaline cartilage

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Discussion and Review
The microscope is a precision instrument that requires some skill and understanding to use properly. This short introduction to the microscope will provide the basic information needed in order to operate it effectively. With some practice, it will become simpler, and with proper care and maintenance, the microscope will provide a view into the world of the microscopic. The Parts of a Light Microscope A light microscope has the following basic systems and parts: Specimen controls - hold and manipulate the specimen.   stage – a square platform where the specimen rests. clips – to hold the specimen in place on the stage. Because a magnified image is viewed with a microscope, the smallest movement of the specimen can drastically alter the field of view. See Figure 2.
Figure 2 – Stage and clips of microscope

Item 1 2

Description Stage Clips

Illumination - lights the specimen. The simplest illumination system is a mirror that reflects room light up through the specimen.
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mirror – held by a C-shaped bracket that plugs into a hole in the base of the microscope, under the stage. The mirror is flat on one side and concave on the other. The concave side focuses the light more strongly.
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Figure 3 – Mirror installed, used to light up the specimen

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illuminator – produces sufficient light where other light sources are not sufficient to see the specimen clearly. The electric illuminator unit attaches to the microscope by plugging it into the hole in the base of the microscope in place of the mirror bracket. condenser – a lens system under the stage that aligns and focuses the light from the lamp onto the specimen. The condenser unit can be removed for cleaning by loosening the set screw on its side. filter – a circular bracket swings out from under the condenser to hold filters that can change the color quality of the light. A blue filter supplied with the microscope makes the color of the illumination from an electric lamp more like natural light or sunlight. See Figure 4. iris diaphragm – built into the condenser unit in the path between the light source (mirror or lamp) and the condenser lenses to alter the amount of light that reaches the specimen. Moving the lever on the side of the condenser unit changes the diameter of the aperture of the diaphragm, varying the amount of light reaching the specimen. This alters the contrast in the image and significantly affects the visual quality of the image. See Figure 5.

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Figure 4– Microscope parts I

Item Description 1 Main tube Nosepiece and 2 lenses 3 Stop-set screw 4 Stage knobs 5 Arm 6 Filter 7 base

objective

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Figure 5 – Microscope parts II

Item 8 9 10 11 12 13 14 15 16

Description Eyepiece Eyepiece tube Main tube Coarse-focus knob Fine-focus knob Stage Diaphragm Inclination joint Light source

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Lenses – form the image.
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objective lens – gathers and focuses light from the specimen. A typical student microscope has 4X, 10X and 40X power objective lenses. eyepiece – transmits and magnifies the image from the objective lens to your eye. A typical student microscope has 10- or 15-power eyepieces. A wide-field eyepiece enables the viewer to see a wider area of the specimen.

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Figure 6 – Objective lenses and eyepiece

Item 1 2

Description Objective lenses Eyepiece

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Focus - to position the objective lens at the proper viewing distance from the specimen.
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coarse-focus knob – brings the object approximately into the focal plane of the objective lens. Refer to Figure 5. fine-focus knob – makes fine adjustments to focus the image. Refer to Figure 5.

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Support and alignment
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arm – the curved portion of the microscope frame that holds all of the optical parts at a set distance from the stage. Refer to Figure 4. base – supports the weight of the microscope. Refer to Figure 4. inclination joint – connects the arm to the base and allows the arm to be tilted toward the viewer for a more comfortable viewing position. Refer to Figure 5. nosepiece – a rotating mount at the bottom of the tube that holds three objective lenses. Refer to Figure 4. tube – blocks out stray light and holds the eyepiece at its top and the nosepiece with objective lenses at its bottom a specific distance apart (for this microscope 160 mm) in order to make the lenses work together optically. Refer to Figure 4. rack and pinion gear – connects the tube to the arm of the microscope. It allows movement of the tube relative to the arm, changing the distance from the objective lens to the specimen in order to focus the image or to move the assembly away from the stage in order to change lenses or slides. stop-set screw – located at the base of the focusing rack and pinion block and behind the rotating nosepiece. The stop-set screw can be set to keep the coarse focus from placing the objective lens so low that it strikes and damages the specimen. Refer to Figure 4.

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Some Microscope Terms:  total magnification – the product of the magnifying powers of the objective and eyepiece lenses (e.g., a 15X eyepiece and a 40X objective lens will together give you 15×40=600 power magnification). resolution – the closest that two objects can be positioned before they are no longer detected as separate objects (usually measured in nanometers). Resolution is related to the numerical aperture of the objective lens (the higher the numerical aperture, the better the resolution) and by the wavelength of light passing through the lens (the shorter the wavelength, the better the resolution).
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brightness – refers to lightness or darkness of the image. It is related to the illumination system and can be changed by changing the strength of the source of light and by adjusting the condenser diaphragm aperture. Brightness is also related to the numerical aperture of the objective lens: the larger the numerical aperture, the brighter the image. focus – refers to whether the image is blurry or well-defined. It is related to focal length and can be controlled with the focus knobs. The thickness of the cover glass on the specimen slide can also affect the ability to focus the image if it is too thick for the objective lens. contrast – refers to the difference in lighting between adjacent areas of the specimen. It is related to the illumination system and can be adjusted by changing the intensity of the light and the diaphragm aperture. Chemical stains applied to the specimen can enhance contrast. numerical aperture – the measure of the light-collecting ability of the lens. depth of field - the vertical distance, from above to below the focal plane, that yields an acceptable image. field of view – the area of the specimen that can be seen through the microscope with a given eyepiece and objective lens. focal length – the distance required for a lens to bring the light to a focus (usually measured in millimeters). focal point – the point at which the light from a lens comes together in a point.

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Care and Handling of the Microscope  When moving the microscope, always use two hands. Place one hand around the arm, lift the scope, and put the other hand under the base of the scope for support. Carry it carefully, ensuring that it does not bang against anything while moving from one place to another. When putting the microscope down, do so gently. If it is banged down on the table, eventually lenses and other parts could get jarred loose. The microscope seems like a simple instrument, but each eyepiece and objective lens is actually composed of a number of lenses put together to create enhanced magnification. If the microscope is mishandled, upwards of 15 to 20 lenses are shaking around! Always have clean hands when handling the microscope.

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Using an Electric Illuminator Grasp behind the mirror bracket and pull the bracket to unplug it from the base of the microscope. Insert the metal plug tip of the electric illuminator into the hole from which the mirror bracket was unplugged. Rotate the fixture so that the glass opening over the bulb points upward toward the light condenser under the stage. Plug the electric cord into a 120 volt outlet and turn on the switch, located on the cord. Using an Oil Immersion Lens Install the oil immersion 100X objective lens in place of any of the other objective lenses. The 4X lens is a good choice. Apply a drop of oil onto the specimen slide and turn the revolving nosepiece to bring the 100X objective lens into position. See Figure 7. If the barrel is too low to allow the 100X lens to move into position, raise it with the coarse focus very slightly, position the lens, and then lower the barrel until the tip of the 100X lens gently touches the oil and the slide. The tip of the lens is able to move a short distance into the lens against a spring in order to keep from putting too much pressure on the slide. With the lens tip touching the oil and slide, focus with the fine-focus knob. The working distance of the lens is very short so do not use the coarse-focus knob other than to carefully position the lens. After using the oil immersion lens, wipe off the oil carefully with alcohol. Cleaning the Microscope   The first step in keeping the microscope clean is to always keep the microscope covered with the dust cover when it is not in use. The eyepiece will need cleaning from time to time. Due to its position on the scope, it will have a tendency to collect dust and even oil from eyelashes. The eyepiece lens should be cleaned with the microfiber cloth that comes with the microscope, with a high quality lens paper, or with a cotton swab. Brush any visible dust from the lens and then wipe the lens. A bit of lens solution may be used, applied to a cotton swab, but do not use facial tissues to clean the lenses. See Figure 8.

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If the eyepiece should collect dust on the interior surfaces, it can be disassembled for cleaning. Slowly unscrew the two parts of the eyepiece, carefully noticing the positions of the lenses (e.g., convex surface up or down) as it opens so that it can be reassembled into the same positions. The objective lenses will occasionally need to be cleaned. Use a clean surface of the microfiber cloth or a fresh cotton swab each time so that no dust is transferred from one lens to another. Clean the lenses in the glass condenser under the stage by loosening the set screw to remove the condenser assembly. The assembly can be unscrewed to remove the lenses, but be sure to notice the positions of the lenses (e.g., convex surface up or down) as it is opened so that it can be easily reassembled in the same positions. Finally, clean the mirror or the glass lens over the illuminator so that an optimal amount of light can shine through. Follow up by wiping the whole microscope with a soft, clean cotton towel.

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Storing the Microscope  The best place to store the microscope is a stable desk, table or shelf where the microscope will not be disturbed or bumped. Dust is not good for the lenses, so always keep the microscope covered with the vinyl cover when not in use. The package fitted foam case that the microscope was packaged in may also be used for storage. See Figure 9.
Figure 9 – The package fitted foam case may be used for storage.

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Exercise 1
In the following activity, the student will have the opportunity to practice using a light microscope.

PROCEDURE
1. Remove the microscope body from the case. Remove the plastic cap closing the top of the tube. Remove the eyepiece from its plastic container, and insert the eyepiece in the opening in the tube. 2. Remove the objective lenses from their individual containers. Unscrew the plastic caps on the revolving nosepiece, and screw the objective lenses into the revolving nosepiece. Place each in the color-coded position that corresponds to the color band on the lens. 3. Adjust the tension on the coarse focus control knobs if necessary. To increase tension, hold one knob firmly in each hand and turn them in opposite directions, each clockwise with reference to the microscope. Turning the knobs counter-clockwise relative to the microscope will loosen the coarse focus tension. 4. Unplug the rotating mirror bracket from the base of the microscope. Insert the mirror (packaged separately with the microscope) into the bracket, firmly spreading the arms of the bracket so that the points on the inside of the tips of the bracket can fit into the depressions on the rim of the mirror. When the mirror swivels freely, plug the bracket back into the base of the microscope. 5. Tilt the arm of the microscope back until it is at a position where the microscope image can be viewed comfortably. 6. Place a slide under the clips on the stage with the designated area to be viewed over the center of the hole in the stage. For the first try, use either the focusing slide or select a specimen from the LabPaq that is relatively large and has some bright color that will be easy to find in the field of view, such as the hyaline cartilage slide. 7. Turn the nosepiece of the microscope to select the longest lens (usually the highest power or 40X lens). Lower the tube of the microscope with the coarse-focus knob until it almost touches the slide. If it will not go that far, unscrew the stop-set screw behind the rotating nosepiece of the microscope until it will let you move the tube down so that the lens can almost touch the slide. While it is in that position, lightly tighten the screw and lock it in place with the knurled (ridged) nut on the shaft of the screw. 8. Place a light source in front of the microscope. Use the small lever on the sub-stage condenser to open the diaphragm fully, and adjust the mirror so that the light is brightest as seen through the microscope. 9. Rotate the nosepiece to select the lowest power lens (4X). Lower the tube with the coarse-focus knob until it reaches the stop that is set (which you have just set above)
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and will not go further. Then raise the barrel slowly with the coarse-focus knob until an image is seen on the slide. Finish the focus with the fine-focus knob. 10. Looking through the microscope, and with thumb and forefinger on each end of the slide, move the slide slowly on the stage until the object to study is centered in the field of view. 11. Rotate the nosepiece of the microscope to select the objective lens for magnification. Once one lens is focused properly, any other objective lens on the nosepiece rotated into position will be roughly in focus, requiring only fine focus or very slight movement of coarse focus to bring the image with the new lens into correct focus. 12. Move the lever for the diaphragm through its full range to select the amount of light that gives the best contrast. Many details will be visible with good contrast, which would be otherwise lost with too much or too little light.

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Questions A. The following statements are true or false. If true, write a “T” on the answer line. If false, write a word or phrase in the blank to make the statement true. ____1) The microscope lens may be cleaned with any soft tissue. ____2) The coarse adjustment knob maybe used in focusing with all objective lenses. ____3) When beginning to focus, the lowest power lens should be used. ____4) Resolution decreases as the amount wavelength of light increases. ____5) When focusing always focus toward the specimen. B. Match the microscope structures in column B with the statements or phrases about them in column A. Column A _____ 1) Platform on which the slide rests for viewing _____ 2) Used for precise focusing after initial focusing Column B a. nosepiece b. eyepiece

_____ 3) Used to increase the amount of light passing through c. stage the specimen _____ 4) Lens located on the superior end of the body tube d. fine focus knob

_____ 5) Carries the objective lenses and rotates to change e. iris diaphragm magnification C. Explain the proper technique for transporting a microscope. D. Define the following terms: field of view: resolution: total magnification: focal length: contrast:

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E. What happens to the size of the field of view as magnification increases? F. What would be the total magnification of a specimen if the eye piece is 15X and the objective lens selected is 4X? G. If observing a specimen on the low power objective, when switching to high power, the specimen is no longer visible. Why did this happen? Conclusions Why is proper microscope technique important for studying Anatomy and Physiology?

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An Overview of Anatomy
Laszlo Vass, Ed.D. Version 10.1.03
Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary

Students will have the opportunity to learn about the anatomical position and observe surface anatomy. They will learn body orientation terms and identify body planes and sections. Students will become familiar with the names of body cavities and organ systems.

© Hands On Labs, Inc. – All rights reserved worldwide.

Objectives
The student will have the opportunity to:  Describe the anatomical position and explain its importance.  Observe surface anatomy.  Identify orientations and areas of the body using proper anatomical terms.  Understand body planes and sections.  Name the body’s cavities and organ systems. Time Allocation: Allow 3 hours for this experiment.

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Materials
Materials Student provides Label or Box/Bag Qty 1 1 1 1 5 3 1 1 Item Description Mirror (full- or partial length) A&P textbook Internet access Kitchen knife Paper towels Potatoes Your own body or a volunteer to serve as an anatomical model Marker

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Discussion and Review
Anatomy, like any other discipline, has jargon unique to its field of study. Anatomical terms are specialized to help identify areas of the body with as few words and as much clarity as possible. The terms given in this exercise are used universally and provide a good introduction to gross anatomy, the study of body structures visible to the naked eye.
Anatomy comes from the Greek word anatomia, which when translated means “to separate” and “to cut open.” Anatomy is the structure of organisms. Humans understand even more about their anatomy since the development of the X-ray, ultrasound, and Magnetic Resonance Imaging (MRI). See Figure 1.

Figure 1 – MRI image of the cross-section of a human knee. The MRI is a technology that allows for the study gross anatomy inside the body of a living human.

Anatomical references are based upon a universally accepted standard body position called the anatomical position. Understanding the anatomical position is important because all anatomical directional references are based on this position of the body. In the anatomical position, the body is standing erect, feet are shoulder width apart, toes are pointing forward, arms are down by the sides, and the palms are facing forward. See Figure 2.

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Figure 2 – Anatomical position

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Exercise 1: Anatomical Position
PROCEDURE:
In the following exercise, the student will use his/her body to learn about anatomical position. 1. Stand in front of a full-length mirror and assume the anatomical position. Note: If a full-length mirror is not available, stand in front of a partial-length mirror. Notice that this position is not particularly comfortable to maintain for a long time. The palms of the hands face forward by the sides of the body, which is not the natural position for the hands. Usually the hands hang loosely and are slightly cupped next to the sides of the body. Question: A. Explain why it is important to have a universally accepted anatomical position when studying the structure of humans.

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Exercise 2: Surface Anatomy
Learning the surface landmarks of the body can be useful when identifying certain regions and areas of the body. In this activity, students will review some of these landmarks, identify them on the body, and label them on a diagram.

PROCEDURE:
1. Some anterior and posterior landmarks of the body are listed in Table 1 and Table 2. Locate each anterior and posterior landmark on your body by pointing to each landmark. Note: This process is not a waste of time. There are many terms, and this process will help you remember them. 2. Become familiar enough with these terms to label each region without referring to the tables. Table 1 – Anatomical terms: Anterior body landmarks Term Abdominal Acromial Antebrachial Axillary Brachial Buccal Carpal Cephalic Cervical Coxal Crural Digital Femoral Fibular Frontal Hallux Description anterior trunk below the ribs point of the shoulder forearm armpit arm above the elbow cheek wrist head neck hip front of the lower leg fingers and toes thigh Lateral (outside) of the lower leg forehead big toe Term Inguinal Mammary Mental Nasal Oral Orbital Palmar Patellar Pedal Pelvic Pollex Pubic Sternal Tarsal Thoracic Umbilical Description groin breast chin nose mouth eye sockets palm of the hand kneecap foot pelvis thumb genitals breastbone ankle chest navel

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Table 2 – Anatomical terms: Posterior body landmarks Term Acromial Brachial Calcaneal Cephalic Dorsal Femoral Gluteal Lumbar Manus Occipital Questions: A. Review Figure 3. Complete the table by placing each letter from the figure next to its corresponding body landmark. Figure 3 – Anatomical landmarks Description point of the shoulder arm above the elbow heel head back thigh buttocks lower back below the ribs hand base of the skull Term Otic Perineal Plantar Popliteal Sacral Scapular Sural Vertebral the ear between the anus and the genitals sole of the foot back of the knee region between the hips on the back the shoulder blade the calf spinal column Description Olecranal posterior of the elbow

Body Landmark 1. Sural 2. Popliteal 3. Tarsal 4. Calcaneal 5. Brachial 6. Cranial 7. Acromial 8. Buccal 9. Axillary 10.Olecranal 11.Occipital 12.Lumbar

Letter

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B. Mr. Shmelgenbelcher has had a rough day. He woke up with a pain in his cervical region. He fell off his bike and bruised his crural region. He pulled a muscle in his inguinal region and was whacked by a revolving door in his scapular region. Describe where each of these areas is located on poor Mr. Shmelgenbelcher’s body.

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Exercise 3: Body Orientation
Anatomists and biologists use a set of terms to describe the general direction in which a region of the body is located. These terms help to indicate where on the body certain areas are located. The terms can also help to narrow down specific body parts by describing where each body part is located in relation to another body part.

PROCEDURE:
1. Review each of the following sets of terms, and identify each directional term in relation to your body. See Figures 4 and 5 for a pictorial representation of these terms. a. Superior/Inferior – toward the head/toward the feet. On the human body, the shoulders are superior to the navel. The knees are inferior to the hips. b. Anterior/Posterior – toward the front/toward the back. On the human body, the face, chest, and abdomen are the most anterior. The spine is considered posterior to the chest. c. Medial/Lateral – toward the midline/away from the midline. The sternum is medial to the ribs. d. Proximal/Distal – toward the trunk/away from the trunk. These terms are used to signify the limbs’ distance from the trunk. The wrist is distal to the elbow but is proximal to the fingers. e. Superficial/Deep – toward the surface of the body/away from the surface of the body. The skin is superficial to the muscles. The bones are deep to the muscles. f. Dorsal/Ventral – backside/toward the belly. These terms are primarily applicable for organisms in which the anterior, ventral, dorsal, and posterior surfaces are in different planes of orientation. Refer to Figure 5. On the human body, anterior, ventral, dorsal, and posterior are synonymous with one another because humans stand on two legs. g. Cephalic/Caudal – toward the head/toward the tail. On the human body, these terms are synonymous with superior and inferior. On other organisms, they are synonymous with anterior and posterior. See Figures 4 and 5.

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Figure 4 – Anatomical directional terms of the human body.

Item 1 2 3 4 5 6 7 8

Description Superior/Cephalic Inferior/Caudal Lateral Medial Anterior/Ventral Posterior/Dorsal Proximal Distal

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Figure 5 – Anatomical directional terms of a fetal pig.

Item 1 2 3 4 5 6 Questions:

Description Anterior/Cephalic Posterior/Caudal Dorsal/Superior Ventral/Inferior Proximal Distal

A. Use the directional terms to fill in the blanks. a. b. c. d. e. f. g. h. The nose is __________ to the ears. The elbow is ___________ to the shoulder and ____________ to the wrist. The heart is __________ to the spine. The stomach is ___________ to the ribs. The pinky finger is ___________ to the thumb. Muscles are __________ to the skeleton. The mouth is ___________ and ___________ to the ears. The brain is ___________ to the spinal cord.

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Exercise 4: Body Planes and Sections
In order to study the body in three dimensions, anatomists divide the body into different sections or cuts. These cuts are often made along an imaginary flat surface called a plane. There are three major planes in the body, which lie at right angles to each other. See Figure 6. Figure 6 – Planes of the human body. Image courtesy of the National Library of Medicine at http://nih.nlm.gov

Item 1

Plane Sagittal (mid-sagittal and parasagittal)

2 3

Frontal (coronal) Transverse (horizontal)

Description Runs longitudinally and divides the body into right and left sections.  The mid-sagittal runs along the median of the body.  The parasagittal is off to one side. Divides the body into anterior and posterior sections. Runs horizontally and divides the body into superior and inferior sections, often referred to as cross-sections.

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PROCEDURE:
1. Obtain three potatoes of any size, a kitchen knife, and several paper towels. 2. Decide which part of the potato is anterior, the posterior, the superior and the inferior. Label “anterior,” “posterior,” “superior,” and “inferior” on all potatoes with a marker. 3. Make a mid-sagittal cut all the way through one potato. 4. Lay one of the sides, open-side-up, and sketch the potato section in the Lab Report. Label “anterior,” “posterior,” “superior,” and “inferior” on the potato drawn in the lab report. 5. Repeat the previous steps for a frontal section and a transverse section. Use a different potato each time. Label “anterior,” “posterior,” “superior,” and “inferior” on the potato drawn in the lab report. Questions: A. Which of the following organs would not be visible if you cut the body in a mid-sagittal section? Explain. a. b. c. d. The brain The stomach The heart The kidneys

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Exercise 5: Body Cavities
The body has a series of internal caverns or cavities separated by bony structures and membranes. Serous membranes line the organs within these cavities to help stabilize and secure the organs, and to keep them from rubbing against each other and causing damage. Of these body cavities, the abdominal region is further divided into quadrants. There are a total of nine abdominopelvic regions. Figures 7 and 8 show the location of the body cavities and abdominopelvic regions. Figure 7 – Cavities of the human body. Image courtesy of the National Library of Medicine at http://nih.nlm.gov

Item 1 2 3 4 5 6 7 8

Description Cranial cavity Thoracic cavity Ventral cavity Abdominal cavity Abdominopelvic cavity Pelvic cavity Spinal cavity Dorsal cavity

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Figure 8 – Nine abdominopelvic regions (left); Quadrants of the abdominal region (right).

Item 1 2 3 4 5 6 7 8 9

Description Right hypochondriac region Epigastric region Left hypochondriac region Right lumbar region Umbilical region Left lumbar region Right iliac (inguinal) region Hypogastric (pubic) region Left iliac (inguinal) region

Item UR UL LR LL

Description Upper right region Upper left region Lower right region Lower left region

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Questions: A. What organs are found in the pelvic cavity? B. If the doctor presses on the right hypochondriac region, what organ is the doctor likely pressing on? C. Describe what is found in the dorsal body cavity. D. What two body cavities may be invaded by a brain tumor?

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Exercise 6: Organ Systems
When anatomists study the body, they use some basic precepts of biology that apply to all living things. Namely, the organization of the human body is dependent on the relationships and inner workings of cells. Cells are grouped together by common functions into structures called tissues. Groups of tissues organized with common functions are called organs. Finally, groups of organs with common functions that are organized together are called organ systems. The human body has eleven organ systems. While each system has its own function, it is important to remember that all of the systems work together to maintain homeostasis. The organ systems of the human body are:  Circulatory: Contains the heart, blood, and blood vessels. The circulatory system delivers oxygen and nutrients to the cells and removes carbon dioxide and metabolic wastes from the cells. See Figure 9. Figure 9 – Circulatory organ system



Digestive – Contains the mouth, esophagus, stomach, small intestine, large intestine, liver, and pancreas. The digestive system processes food and nutrients for use in the body through mechanical and chemical digestion and eliminates solid wastes. Endocrine – Contains glands in various parts of the body. The pituitary gland in the brain is a major endocrine gland. The pancreas, thyroid, testes, and ovaries are other glands found throughout the body. The endocrine system regulates all other systems by releasing hormones into the blood.



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 

Integumentary – Contains the skin, hair, and nails. The skin forms a protective barrier that helps insulate the body from infection and disease. Immune – A functional system without specific organs of its own. The immune system provides protection against foreign pathogens like bacteria, viruses, and parasites. The system uses white blood cells, lymph nodes, tonsils, and the spleen to provide its function. Lymphatic – Contains lymph, lymph vessels, lymph nodes, and glands like the tonsils and spleen. The lymphatic system functions in filtering the blood of foreign impurities and houses white blood cells to provide immunity for the body. Muscular – Contains the three muscle types (skeletal, smooth, and cardiac). The muscular system provides movement for the body, digestion, and assists in the circulation of the blood. Respiratory – Contains the lungs, trachea, mouth, and nasal sinuses. The respiratory system provides a gas exchange of oxygen and carbon dioxide between the air and the cells in the body through the circulation of the blood. Reproductive – Contains the organs and cells needed to create offspring. The reproductive system contains the male and female reproductive structures, primarily the testes and ovaries. The system relies heavily on the endocrine system and hormones to function correctly. Skeletal – Contains the bones and cartilage. The skeletal system provides support and protection and aids in body movement. Urinary – Contains the kidneys, bladder, ureters, and urethra. The urinary system filters the blood to remove metabolic wastes and creates urine as a medium by which to excrete these wastes from the body.

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

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 

While each system has a set of specific functions, it is important to remember that the body works as a unit of systems. Each set of organs contributes to the function of the whole body – the organism.

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Questions: A. Complete the following table by filling in the missing system name, major organs, or functions.
Organ System 1. 2. 3. Lymphatic/Immunity 4. 5. 6. Urinary 7. 8. 9. Nervous 10. 11. Epidermal and dermal regions; contains cutaneous sense organs Contracts and shortens to provide movement. Generates heat for the body. Bones, cartilages, tendons, ligaments, and joints Transports oxygen and nutrients to the cells and removes carbon dioxide and waste from the cells through the blood. Pituitary, thymus, thyroid, adrenal glands, testes, ovaries Breaks down food into molecules for absorption into the blood. Removes undigested wastes. Major Organs Nasal passages, pharynx, larynx, trachea, lungs Functions

Provides cells to perpetuate the species.

B. Describe how cells, tissues, organs, and organ systems are related to each other. C. A jogger steps into a pothole and sprains his ankle. Describe all of the organ systems that would be affected or involved in this injury. As a hint, think about the symptoms of a sprain and what system would be involved with each symptom. Conclusion: You have reviewed many terms in this experiment. Describe some strategies that may be used to help retain this information.

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Histology
Laszlo Vass, Ed.D. Version 09.1.03

Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will have the opportunity to learn about the functions and locations of tissue types in the human body using prepared slides. They will learn the similarities and differences of four tissue classifications: epithelial, connective, muscular, and nervous.

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Objectives
The student will have the opportunity to:  Name and identify the major tissue types in the human body.  Identify the subcategories of tissue types through microscopic identification and inspection of corresponding photomicrographs and diagrams.  State the location of the tissue types in the body.  Identify the major functions of each of the tissue types in the body. Time Allocation: Allow 3 hours for this experiment.

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Materials
Materials Student provides LabPaq provides Label or Box/Bag Qty 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Item Description Microscope and Internet access Slide - Cardiac muscle LS Slide - Dense regular connect Slide - Elastic cartilage Slide - Fibrocartilage Slide - Ground compact bone CS Slide - Human blood Slide - Hyaline cartilage Slide - Pseudostrat. ciliated Slide - Reticular connective Slide - Simple column-duodenum Slide - Simple column-stomach Slide - Simple cuboidal Slide - Simple squamous Slide - Skeletal muscle L&CS Slide - Skeletal muscle w/ neuro Slide - Smooth muscle LS Slide - Spinal Cord Smear Slide - Stratified squa. non-k Slide - Stratified squamous Slide - Transitional epithelium

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Discussion and Review
Histology is the study of the microscopic anatomy of cells and tissues. Tissues are defined as a group of cells that provide a unified function for an organism. Understanding the structure and function of various tissues is important for studying organs and systems. Since Anatomy and Physiology are based upon the complementarity of form and function, the structure of these tissues can provide clues about their purpose in the human body. In this exercise, the student will explore the various classes of tissues to learn about their structure and function. There are four classifications of tissues: epithelial, connective, muscular, and nervous. Each of these tissue classifications has unique characteristics that define function.  Epithelial tissue: Epithelial tissue covers the body and linings of the body to protect the internal environment. Epithelial tissue regulates the exchange of material between the internal and external environment. It is found on the body as skin, linings of body cavities, and linings of vessels. Connective tissue: Connective tissue provides support for structures of the body and often acts as a physical barrier from injury. Connective tissue, with specialized cells, may help defend the body from foreign invaders. Connective tissues include blood, bone, cartilage, and support structures for internal organs and the skin. Muscular tissue: The function of muscular tissue is to provide contractions for producing force and movement. Muscle tissue is found throughout the body. There are three types of muscle tissue: skeletal, smooth, and cardiac muscle. Nervous tissue: Nervous tissue carries information in the form of electrical/chemical signals from one part of the body to another. Nervous tissue is found in large concentrations in the brain and spinal cord, but it reaches nearly every part of the body. See Figure 1 for a representation of a nerve cell.

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Figure 1 – Drawing representation of a Purkinje nerve cell of the cerebellum

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Exercise 1: Epithelial Tissue
Epithelial tissue covers surfaces in our body. It can be external, such as the epidermis of our skin, or internal, such as the linings of our tubules and cavities. Functions include protection, absorption, filtration, secretion, excretion and sensory reception. Scientists classify epithelial tissues based on their arrangement and shape. Epithelial cells are arranged in two ways: simple, meaning a single layer of cells and stratified, meaning multiple layers of cells. Their shapes include squamous (flat), cuboidal (cube-like) and columnar (column-like). There are also two unique arrangements and shapes that do not fit into the above categories. The first is pseudostratified epithelium. The word “pseudo” means false, so this classification of tissue implies that the cells appear to have multiple layers, but they are actually a single layer of cells. The size of cells varies, as does the location of the nucleus within the cells giving the impression of layering. The second type of unique epithelial tissue is transitional epithelium. Transitional epithelium has large, rounded cells with the unique feature of sliding or moving past one another. This allows the tissue to stretch. Figure 2 shows drawings of the different types of epithelial cells.
Figure 2 – Types of Epithelium

Item 1 2 3 4 5 6 7

Description Simple squamous Simple cuboidal Simple columnar Transitional Stratified squamous Stratified cuboidal Pseudostratified columnar

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At the base of the epithelial tissue, a layer of collagen and laminin filaments holds the epithelial tissue to the underlying structure. This layer is called the basal lamina or basement membrane. It is almost like glue for the epithelial cells and the underlying structure. Epithelial tissue may have some physical features that allow it to function differently in various parts of the body. For example, in areas of the body where movement of particles is necessary, the epithelial cells may have cilia. Cilia beat rhythmically to promote the movement of particles. See Figure 3.
Figure 3 – Cilia in respiratory epithelia. In respiratory epithelia, mucus traps foreign particles. Cilia beat upward to move these foreign particles toward the mouth so they can be spit out or swallowed instead of entering the lungs.

In this exercise, you will examine the various types of epithelial tissues under the microscope. Remember, the objective is to relate structure and function. Reference your textbook and the photomicrographs on the Hands-On Labs website to help you with this exercise.

PROCEDURE
1. Retrieve the prepared slides of simple squamous, simple cuboidal, simple columnar, stratified squamous (keratinized and non-keratinized), pseudostratified ciliated columnar, and transitional epithelium. 2. Place the slide of simple squamous epithelium on the stage of the microscope. 3. Start on low power and focus the slide. Switch to medium power and refocus. Finally, switch to high power and sharpen the image with the fine focus. Note how the epithelial cells fit in close to each other to form sheets of cells. This allows the tissue to make an effective covering.
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4. Scan the slide for specific functions such as cilia (cell projections to help move materials) or microvilli, which increase surface area for greater absorption. 5. For reference, compare the observations to the online photomicrographs of each slide in the slide table found at: http://www.labpaq.com/ex-2-histology. These online examples are labeled and will help ensure that the structures and features on the observed slides for this exercise are correctly identified. 6. Repeat Steps 3 to 5 for each of the epithelial tissue slides. Pay particular attention to details such as cell size, shape, arrangement, and layering as well as features such as cilia or microvilli in each of the slides you observe. 7. Record the descriptions of the epithelial tissues you observed with the microscope into the lab report Data Table 1. 8. Closely observe the online photos of stratified cuboidal epithelium and stratified columnar epithelium tissue slides. Look for the same details in cell size, shape, arrangement and features that you looked for with the microscope slides and record your observations into the lab report Data Table 1.
Data Table 1 – Epithelial Tissue Observations TISSUE TYPE Simple Squamous Simple Cuboidal Simple Columnar (stomach) Simple Columnar (duodenum) Stratified Squamous (keratinized) Stratified Squamous (non-keratinized) Pseudostratified Ciliated Columnar Transitional Stratified Cuboidal (online) Stratified Columnar (online) OBSERVATIONS

Questions A. Why is the study of histology important in the overall understanding of anatomy and physiology? B. How are epithelial tissues named? C. Why are some epithelial tissues stratified? D. Unlike squamous cells, cuboidal and columnar cells have large, open cytoplasm. Which functions of epithelial tissue are supported by having such big cells?

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E. Look at the following drawings and identify each type of epithelial tissue:

1.______________________

2._____________________

3.______________________

4.______________________

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Exercise 2: Connective Tissue
Connective tissues are the most abundant tissues in the body. Connective tissues perform a variety of functions. They protect, support and bind together the other tissues of the body. Connective tissues contain a variety of cells, but much of the connective tissue in the body is non-cellular matter between the cells called the matrix. This matrix is the key to providing supportive, protective, and binding functions of connective tissues. The cells make and extrude the matrix that surrounds them. Some connective tissues also contain collagen fibers. The fibers allow tissues to be flexible while providing additional strength and stability.
Figure 4 – Reticular fibers, a type of connective tissue in the human liver. Reticular fibers are also found in the bone marrow and lymphatic system tissues.

PROCEDURE
In this exercise, you will examine the structure and functions of connective tissues. Pay particular attention to the shape of the cells, and the amount of non-living matrix between the cells. Look for the presence of fibers running between the cells. 1. 2. Prepare a table similar to Data Table 2 below to record observations while performing the experiment. Closely observe the online photo of the Mesenchyme tissue slide. Look for details such as cell shape, cell size and arrangement, amount of matrix, and fibers. Mesenchyme is infantile tissue, which serves as the base for several connective tissues in the body. Repeat step 2 for areolar, adipose, and dense irregular connective tissues. Areolar tissue is found in almost all parts of the body and is a loose connective tissue. Adipose tissue is composed of fat cells. Dense irregular connective tissue is found in the white portion of the eyeball, the dermis of the skin, and the outer layer of bone.

3.

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4.

Closely observe each of the following slides with the microscope using low power to focus and high power with fine focus for detailed observation: dense regular connective tissue (tendon), reticular tissue, ground compact bone, human blood, hyaline cartilage, elastic cartilage, and fibrocartilage. Hyaline cartilage is found on the articular surfaces of bones, elastic cartilage is found in the outer ear, larynx, and epiglottis, and fibrocartilage is found in intervertebral discs and the menisci of the knee. For each slide, record the shape and number of cells present into lab report Data Table 2. Observe the matrix between the cells. Note how much open space exists between the cells and the matrix: a little or a lot? Are there fibers present? If so, how many?
Data Table 2 – Connective Tissue

5. 6.

Tissue Mesenchyme (online) Aerolar (online) Adipose (online) Dense Irregular (online) Reticular Dense Regular: Tendon Hyaline Cartilage Elastic Cartilage Fibrocartilage Compact Bone Human Blood

Amount and Shape of Cells

Amount of Matrix

Are there fibers? If so, are they parallel or scattered?

Questions A. B. C. D. E. What is the primary function of connective tissue? What can the shape of the cells in a particular type of tissue tell about the function of that tissue? What is matrix? Why do some tissues have more matrix than others? What do collagen fibers provide? Tendons, ligaments and cartilage have limited blood supply. Explain how this might affect the ability of these tissues to heal after an injury.

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Exercise 3: Muscle Tissue
Muscles are highly specialized tissues that are designed to contract and extend when force is applied to them. Their primary function is movement, but they also play a major role in body temperature regulation, digestion, respiration and circulation. There are three types of muscles in the body. The most common muscle type is skeletal muscle, which is under voluntary control from the brain and provides strength to move the limbs and body. Skeletal muscle is both strong and flexible. The second type of muscle is smooth muscle. Smooth muscles make up the bodies of the internal organs and are designed to stretch and extend. They give up strength to have elastic characteristics and are therefore vulnerable to injury. The last type of muscle is the highly specialized muscle only found in the heart called cardiac muscle. Cardiac muscle is composed of a series of cells that work together as one unit and respond to electrical impulses that allow the heart to beat. The primary function of cardiac muscle is to send blood through the arteries to deliver nutrients and oxygen to cells. The man in Figure 5 is running. He is utilizing all types of muscle: skeletal, cardiac, and smooth muscle, to keep his body moving and oxygenated during aerobic exercise. Skeletal muscle maintains posture and moves his arms and legs. Cardiac muscle in the heart pumps blood to the lungs and then out through the body. Smooth muscle in his arteries aids in moving the blood throughout the circulatory system.
Figure 5 – This man is utilizing skeletal, cardiac, and smooth muscle to keep his body moving and oxygenated for aerobic exercise.

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PROCEDURE
In this exercise, you will observe the structures of the three different types of muscle tissue. Pay particular attention to the shape, size and number of cells. Also, look for banding of the tissue, or stripe-like coloring. These “stripes” are called striations and they run perpendicular to the surface of the cells. 1. Prepare a table similar to Data Table 3 below to record observations while performing the experiment. 2. Closely observe the prepared skeletal muscle slide on the stage of the microscope, using low power to focus and high power with fine focus for detailed observation. 3. Observe the shape of the cells and make note of their arrangement. Look for banding or striations across the cells and fibers. Look carefully for darker oval shaped structures. These will be the nuclei of the muscle cells. 4. Observe the online photomicrographs of skeletal muscle tissue. Compare what is seen on the slide with that of the slide on the LabPaq website. Record your observations. 5. Repeat the above steps 2 through 4 for the smooth and cardiac muscle slides.
Data Table 3 – Observations Prepared Slides Cell Shape and Arrangement Muscle Skeletal Smooth Cardiac Striations Present? Online Slides Cell Shape and Arrangement Striations Present?

Questions A. B. C. D. What kind of muscle would you find in the stomach? How is smooth muscle structure different from that of skeletal and cardiac muscle? Why is skeletal muscle voluntary? What is unique about cardiac muscle?

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Exercise 4: Nervous Tissue
Nervous tissue is specialized to send electrical signals that inform the central nervous system of changes in the environment or body. External sources such as light and sound, or internal sources such as hunger or thirst cause physical or chemical changes to occur in the body. These changes direct a signal that travels via nervous tissue to inform the central nervous system of these changes. Nervous tissue is made of two different types of cells. Neurons receive the stimuli and transmit the impulses through our bodies. Neuroglia are special types of supporting or “helper” cells that protect and insulate the neurons. We usually refer to neurons and neuroglia together as nerves, which are a set of neurons designed to respond to and transmit specific stimuli from a certain area of the body. Nervous cells have a unique shape. These cells have long projections that extend outward. The projections may receive or send signals. The nervous cells receive signals through structures called dendrites, and send signals out of the cell through structures called axons. The amount and shape of dendrites or axons that a nervous cell has varies. Dendrites and axons allow neurons to communicate with other cells of the body. Schwann cells in the peripheral nervous system and oligodendrocites in the central nervous system may wrap the projections with a fatty substance called myelin, which allows the signals to travel faster. The cell body, or soma, of the neuron contains the nucleus and other organelles that maintain the neuron throughout its life. See Figure 6.
Figure 6 – Motor neuron: sends signal to skeletal muscle in the peripheral nervous system.

Item 1 2 3 4 5 6

Description Dendrite Soma (cell body) Axon Schwann cell Myelin sheath Nucleus

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PROCEDURE
In this exercise, you will observe the microscopic structure of neurons. These cells are very different from the ones seen in Exercises 1-3. The cell bodies are large and the cytoplasm is stretched or elongated out into finger-like processes that can be up to 3 feet long. This elongation allows neurons to transmit impulses over a long distance in the body. As observations are made in this exercise, pay attention to the size of the cells and the cell body. Identify the nucleus and find any of the neuroglia or supporting cells surrounding the cell body. 1. Closely observe the online slide microphotograph of the neuron. 2. Closely observe the prepared spinal cord smear slide on the stage of the microscope, using low power to focus and high power with fine focus for detailed observation. Scan the slide and find a multipolar neuron. 3. Compare observations of the prepared neuron slide to the online slide. Write a detailed description of the prepared slide. Include the size and shape of the cell, and how the cell resembled or how the cell differed from the online slide. Questions A. What is the function of nervous tissue? B. Why are the cell bodies of neurons elongated into cell processes? C. If all nerves respond to stimuli, why cannot eyes “hear” sound and ears “see” light? D. How is a nerve different from a neuron? Conclusions: Explain the purpose of these exercises and why studying histology is important to the understanding of how the human body functions.

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Classification of Body Membranes
Laszlo Vass, Ed.D. Version 09.1.02
Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe work space in which to complete the exercise.

Experiment Summary The students will have the opportunity to learn the functions and locations of the membrane types in the human body through microscopy and dissection. Students will inspect a frozen beef joint ball and socket to identify different membrane types and functions, focusing specifically on the structure of synovial membranes.

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Objectives
The student will have the opportunity to:  Recognize the microscopic structure of mucous and serous membranes.  Describe the structure of synovial membranes.  List the major functions of each membrane type and indicate its location in the body. Time Allocation: Allow 5 hours for this experiment.

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Materials
Materials Student provides Label or Box/Bag Qty 1 1 1 Item Description Microscope Internet access to view online materials A longitudinally cut, fresh or frozen beef joint (ball and socket joint from the shoulder or femur) from the meat department in a grocery store Dissection-kit with 7-tools - including the following: Bent Probe, Dropping Pipette, Probe, Ruler in pocket, Scalpel with 2 Blades - Note blades are in the pocket, Scissors, Tweezers Dissection Tray #2 Small, opaque - Note several supplies are loaded in this tray see below Gloves packages - 4 pairs Slide - Pseudostrat. ciliated Slide - Simple column-duodenum Slide - Simple column-stomach Slide - Stratified squa. non-k Slide - Stratified squamous

LabPaq provides

1

1 1 1 1 1 1 1

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Membranes cover body surfaces, line body cavities, and form protective sheets around organs. Membranes are classified in several different ways.  Cutaneous membrane is the skin. The epidermis – outermost layer – is composed of dry, keratinized cells designed to protect the body from invasion by bacteria and viruses. These cells are tough and “dead,” because they no longer contain viable DNA that invaders can use for reproduction. See Figure 1. Figure 1 – The cutaneous membrane on a human body is the skin.



Epithelial membranes are composed of an epithelial sheet attached to an underlying layer of connective tissue. These membranes line cavities that open to the outside of the body, namely the respiratory, digestive, and urogenital tracts. Types of epithelium are based upon shape. If epithelial cells are flat in shape, they are called squamous; if they are cube-shaped, they are called cuboidal; and if they are columnshaped, they are called columnar. When cells are stratified, it means they are found in layers. When cells are called transitional, it means they can contract and expand in areas of the body like the ureter or bladder. See Figure 2.

Figure 2 – Types of epithelium Item 1 2 3 4 5 6 7 Description Simple squamous Simple cuboidal Simple columnar Transitional Stratified squamous Stratified cuboidal Pseudostratified columnar

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Some hollow areas of the human body, though located inside the body, are actually classified as the external environment. The digestive system is an example. Consider what properties for this type of a membrane might be beneficial, including selectivity of transport across a cell membrane, thick layers of cells between the external and internal environment, and cells joined together tightly so materials cannot pass through easily.

Consider function for each type of epithelial cell. There are five functional types of epithelial membranes: exchange, transporting, ciliated, protective, and secretory. Each type is different based on function. These types of epithelial tissue are outlined in Table 1. Table 1 – Five functional types of epithelial membranes. Type of Epithelia Exchange # of Layers 1 Cell Shape Squamous Characteristics Flat cells and pores allow easy passage of molecules for exchange. Location in Body Lungs, blood vessels

Transporting 1

Columnar or cuboidal

Cells are held tightly together to protect movement of material between cells. Intestine, kidneys, Folding of membrane or villi some exocrine glands is present to increase surface area. Cilia are present to move fluid across the surface. Cells are held tightly together to protect movement of material across membranes. Upper airways, female reproductive tract Skin, lining of mouth, cavities open to environment Exocrine glands, such as pancreas; endocrine glands that secrete hormones; sweat glands, salivary glands

Ciliated

1

Cuboidal or columnar Squamous in surface layers, polygonal in deeper layers Columnar to polygonal

Protective

Many

Secretory

1 to Many

Cells are present in the top layer of the tissue that secretes a substance.

Mucous membranes or mucosae are composed of epithelial cells lying on top of loose connective tissue. Serous membranes are epithelial cells that are attached to a small amount of aerolar connective tissue. These membranes are unique because they occur in two layers. The parietal layer lines a body cavity, while the visceral layer covers the organs in that cavity. These membranes cover cavities which, with few exceptions, do not open the
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outside of the body. They also secrete serous fluid, which lubricates the organs and reduces friction between them. Synovial membranes are composed entirely of connective tissue and are found lining the cavities around the joints. These membranes help provide a smooth surface for the movement of joints. They also secrete synovial fluid, which helps lubricate and reduces friction between bones in a joint. See Figure 3. Figure 3 – Example of a synovial membrane

Item 1 2

Description Synovial membrane Synovial fluid

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Exercise 1: The Microscopic Structure of Cutaneous Membranes
In this exercise, students will observe keratinized stratified squamous epithelial tissue from human skin under a microscope. Cutaneous membranes like the skin need to be layered (stratified) in order to provide protection. The specialized protein keratin provides the protective barrier the skin needs. The outer-most cells of the skin are dead, which means that viruses and bacteria cannot use these cells for reproduction. The skin is also very efficient. The keratinized layer protects the body from 70% of all infectious bacteria and viruses it touches.
Keratin makes up a large portion of our nails and hair. The hooves and horns of animals are also mostly made of keratin. Silk fibroins, which insects and spiders produce, are also frequently classified as keratins, though it is unclear whether they are truly related to vertebrate keratins.

PROCEDURE:
1. Place the prepared slide of the keratinized stratified squamous epithelial tissue on the stage of the microscope. a. Focus the slide on low power. b. Find the darker stained keratinized cells on the edge of the tissue sample. The darker stain results from the layering of the keratinized cells. c. Switch to high power and observe the slide. 2. Access the Internet and https://labpaq.com/ap1. go to the Hands-On Labs, Inc. website at

3. Click the link for #3 Body Membranes.” 4. Click the Skin link to view the keratinized, also referred to as cornified, stratified squamous epithelium slide. 5. Compare the microscope slide to the one online. 6. Sketch your observations from the microscope slide in the lab report assistant. Indicate the keratinized layer on the sketch and describe the observed structures and cells.

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Questions: A. What is keratin? B. Why is the skin keratinized?

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Exercise 2: The Microscopic Structure of Mucous Membranes
In this exercise, students will observe various mucous membranes under the microscope. These tissues contain specialized mucous storage cells called goblet cells. The goblet cells are found in the cytoplasm and have a large vacuole where the mucous is stored. Note how the goblet cell is shaped in Figure 4. Figure 4 – Transverse section of a villus from the human intestine. The arrow points to a goblet cell.

PROCEDURE:
1. Place the prepared slide of pseudostratified ciliated columnar epithelium of the trachea on the stage of the microscope. a. Set the objective to low power. b. Turn on the light and begin focusing the slide while looking for the cell types mentioned in the Discussion and Review section. c. Switch to medium power and then high power using the fine focus to adjust the sharpness of the image. 2. Sketch the observations from the microscope slide in the Lab Report. Label the type of epithelium tissue and the goblet cells observed. 3. Repeat the previous steps for the stratified squamous epithelium (non-keratinized) of the esophagus and simple columnar epithelium (duodenum) of the small intestine.

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Questions: A. Compare and contrast the roles of the three mucous membranes. B. What is the role of mucous in the body?

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Exercise 3: Observing Synovial Membrane
PROCEDURE:
1. Place the beef joint on the dissection tray. 2. Find the surface of the joint capsule and feel the texture of the synovial membrane. Refer to Figure 5. 3. Turn the bone so to observe how the synovial membrane is positioned on the bone below. 4. Using the dissection needle from the dissection kit, poke a hole through the superior end of the ball of the joint. Lift a piece of the membrane and the cartilage underneath. 5. Use the tweezers from the dissection kit to carefully peel back a piece of the membrane. Observe the thickness of the section that was peeled back. Figure 5 – Section of a ball-and-socket shoulder joint.

Questions: A. What is the function of the synovial membrane? B. Rheumatoid arthritis results in part from an infection and immune response in the synovial membrane. What effect does this have on the ability of this membrane to carry out its functions? C. Complete Data Table 1.

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Data Table 1 Membrane Cutaneous Mucous Serous Synovial Conclusion: Research pleurisy, peritonitis, and pericarditis. What are these conditions and how do they affect homeostasis in the body? Tissue Types (epithelial/connective) Common Location Functions

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The Integumentary System
Laszlo Vass, Ed.D. Version 10.1.03
Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary

Students will have the opportunity to learn about structures and functions of skin. They will discuss some of the clinical conditions that can affect skin.

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Objectives
The student will have the opportunity to:  Describe the functions of the skin.  Recognize and identify the following structures on both a microscopic slide and diagram: epidermis, dermis, hair follicles, sebaceous glands, and sweat glands.  Compare the functions of the epidermis, dermis, and subcutaneous tissue.  Describe how blood is supplied to the skin.  Describe the distribution and function of sebaceous glands, sweat glands, and hair.  Recognize and discuss the effects of aging on the skin.

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Materials
Materials Student provides LabPaq provides Slide Box AP-1 Label or Box/Bag Qty Item Description 1 Microscope & Internet Access to view online materials 1 Slide - Cover Glass - Cover Slip Cube 1 Blank Slide 1 Slide - Stratified squamous

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Discussion and Review

The largest organ in the body, in terms of sheer square footage, is your skin. The skin, or the integument, is an intricate set of cells and tissues designed to do several important things. The skin is a cutaneous membrane and is designed to cover the outer surface of tissues. The skin has many functions, most of which are involved in protection of the internal structures. The skin insulates the body from both heat and cold, cushions against impact, and prevents damage from chemicals, burns, cuts, and bacterial invasions. Skin is continually renewed. Every minute, one person sheds about 50,000 skin cells. Around the world, the atmosphere contains about a billion tons of dust from dead skin.

Skin excretes urea, salts and water through sweat. See Figure 1. The skin is filled with capillaries that send blood to the surface of the body to regulate temperature. The skin has metabolic functions in the form of vitamin D synthesis for the body. The skin also contains all of the cutaneous sense organs for touch.
Figure 1 – Sweat excreted through the skin helps the body regulate temperature.

The skin has two primary layers. The epidermis, which is the outermost layer consisting of keratinized squamous epithelium and the dermis which is the deeper layer that consists of dense irregular connective tissue. The Epidermis : The epidermis has several different types of cells. The following is a list of these cells and their functions.  Keratinocytes: These cells produce keratin, which is a fibrous protein that gives the skin its protective properties. Keratinocytes are the most abundant cells in the epidermis. Melanocytes: These cells produce a brownish-black pigment called melanin. Melanin provides protection to deeper cells from ultraviolet radiation. Melanin also allows the skin to tan in response to ultraviolet radiation exposure. See Figure 2.



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Figure 2 – Melanocytes produce melanin, a pigment in the skin

Item 1 2

Description Melanocyte Melanin (pigment)

 

Merkel cells: These cells form sensitive touch receptors on nerve endings. Most Merkel cells are found where the epidermis and dermis meet. Langerhans’ cells: These small cells are involved in the immune response of the skin.

The epidermis is divided into four layers in areas where the skin is thinner (most of the body) and five layers in areas where the skin is thicker (palms of the hands, and soles of the feet). The following are the layers of the epidermis from deepest to most superficial.  Stratum basale: The stratum basale is a single layer located just above the dermis. These cells are constantly undergoing cell division to produce millions of new skin cells daily. Melanocytes make up as much as 25% of this layer. Stratum spinosum: Just above the stratum basale layer is the multicellular spinosum. This layer has thick bundles of protein. These are the last cells to receive nutrients from the dermis and as the newly formed daughter cells are pushed superficially, they die. Stratum granulosum: This is a thin layer that has small particles called granules within it. Lamellated granules contain lipids that provide waterproofing for the skin. As the cells move up through this layer, they will die. Stratum lucidum: A thin layer of flattened keratinocytes only found in thick skin (palms of the hands, soles of the feet). Stratum corneum: The outermost layer of the epidermis composed of 20 to 30 squished and flattened layers of dead keratinocytes. These cells slough off every day and are replaced by cells from below. See Figure 3.





 

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The Dermis: The deeper layer of the skin is the dermis and consists of dense, irregular connective tissue. This is the major “living” portion of the skin and contains all of the accessory structures that give the skin its secondary functions. The dermis varies in thickness just like the epidermis and mirrors the epidermis being thicker on the palms of the hands and soles of the feet and thinner on other areas of the body. The dermis consists of the following two layers.  Papillary layer: This is the superficial layer of the dermis and is made of areolar connective tissue and fingerlike projections called dermal papillae that extend up to the epidermis. These projections make ridges in the palms of the hands and the soles of the feet. The papillary layer has numerous capillary beds delivering nutrientrich blood to the skin and allowing for temperature regulation of the body by radiational cooling through the skin. In addition, pain receptors and touch receptors (Meissner’s Corpuscles) are found here. Reticular layer: Below the papillary layer is the deepest layer of the skin called the reticulum or reticular layer. This layer is made up of dense irregular connective tissue and houses arteries, veins, sweat glands, sebaceous glands, hair root follicles, and the deep pressure receptors (Pacinian Corpuscles). See Figure 4.



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PROCEDURE
1. Study Figure 5.
Figure 5 – Skin Diagram

Item 1 2 3 4 5 6 7 8 9 10 11 12

Description Sweat pore Dermal papilla Sensory nerve ending Epidermis Dermis Subcutis (hypodermis) Pacinian corpuscle Sweat gland Hair follicle Sebaceous gland Arrector pili muscle Hair shaft

(National Library of Medicine at http://nih.nlm.gov)

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2. Create a table similar to Data Table 1 and fill in the names of the diagram in the laboratory assistant.

Data Table 1 – Key for Figure 1 2 3 4 5 6 7 8 9 10 11 12

Questions A. How does the skin tan when exposed to ultraviolet light? B. Describe the functions of the epidermis. C. Describe the functions of the sweat glands. D. Compare the structure of the epidermis to that of the dermis. E. Fill in the following table by either inserting the name of the structure/cell or by giving its function(s): Structure/Cell Langerhans cells Found on nerve endings Stratum lucidum The blood supply here provides radiational cooling
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Function(s) Makes a pigment for tanning

Exercise 2: The Microscopic Structure of Skin
In this exercise, you will observe keratinized stratified squamous epithelial tissue from human skin. Cutaneous membranes like our skin need to be layered (stratified) in order to provide protection. The specialized protein called keratin provides the protective barrier that our skin needs. The outer most cells on your skin are dead, which means they cannot be used by viruses and bacteria for reproduction. The skin is very efficient. The keratinized layer protects us from 70% of the all infectious bacteria and viruses we come in contact with. Use the photomicrograph below to help you with the identification of your own slide
Figure 6 – Photomicrograph of skin

PROCEDURE
6. Place the prepared slide of the keratinized stratified squamous epithelial tissue on the stage of the microscope. Focus the slide on low power. Find the darker stained keratinized cells on the edge of the tissue sample. The darker stain results from the layering of the keratinized cells. Switch to high power and observe the slide. Go to the LabPaq Website. Either click on this link or copy and paste it into your browser: https://labpaq.com/ap1

7.

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8. 9.

Click on the following link: “#3 Body Membranes.” Click on “Skin” and compare the microscope slide to the one online. Sketch the slide in the appropriate place in the lab report template and indicate the keratinized layer on the sketch.

Questions A. Compare your slide to the photomicrograph example in the lab procedure. How are they the same and how are they different? Propose a reason why there may be several differences between different slides of skin. B. What is keratin? C. Why is skin keratinized?

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Exercise 3: Clinical Conditions of the Skin
Humans are visual by nature, as are other primates. Humans observe visual cues from each other’s surfaces, namely the skin. Tanning, blushing, acne, and wrinkles (just to name a few) are all conditions of the integument that give nonverbal cues to other humans. In this exercise, explore some of the clinical aspects of the skin and examine the effects of these conditions on the integument.

PROCEDURE
1. Go to the skin cancer society web site http://www.skincancer.org/skin-cancervideo.html and watch the video tutorial on the development and types of skin cancer. 2. Answer the questions in the lab report on skin cancer. 3. Go to http://www.nlm.nih.gov/medlineplus/tutorials/acne/htm/index.htm and complete the tutorial for acne. You can play either the interactive tutorial or the selfplaying tutorial since they both contain the same information. 4. Answer the questions in the lab report assistant about acne. 5. Go to http://www.nlm.nih.gov/medlineplus/tutorials/burns/htm/index.htm and complete the tutorial on burns. You can play either the interactive tutorial or the selfplaying tutorial since they both contain the same information. 6. Answer the questions in the lab report assistant on burns. 7. Go to http://www.webmd.com/skin-problems-and-treatments/guide/elderly-skinconditions to read about the effects of aging on the skin. Be sure to click on the tabs at the top to read about symptoms and treatment in addition to the overview page where you started.

Questions A. What are the three types of skin cancer? B. Which type of skin cancer is easily treatable? C. Explain why melanoma is so dangerous. D. What factors can cause acne? E. What is a common myth about the cause of acne? F. What are some treatments for acne?

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G. Describe the signs of first, second and third degree burns. H. What are the principle effects of aging on the skin?

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Overview of the Skeletal System
Laszlo Vass, Ed.D. Version 09.1.05
Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will have the opportunity to use a skeletal model and dissection specimens to learn about the skeletal system and its components. They will explore the major types of bones and cartilage in the skeletal system and learn how the structure of the bone tissue contributes to the function of the skeletal system.

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Objectives
The student will have the opportunity to:  List the functions of the skeletal system.  Identify the four main kinds of bones.  Identify the structures of a cut long bone.  Identify and give the functions of the microscopic structures found within bone tissue.  Identify and give the functions of the three major types of cartilage in the skeletal system. Time allocation: 2 hours preparation time; 3 hours to perform the experiment. IMPORTANT: Preparation should start 48 hours prior to performing this experiment.

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Materials
Materials Student provides Label or Box/Bag Qty 1 1 1 1 1 1 LabPaq provides 1 1 1 Item Description Bowl with lid or plastic wrap to cover Baking sheet or pan Kitchen oven Microscope Concentrated lemon juice in a bottle Two chicken leg (drumstick) bones with all the meat removed Internet Access to view online materials Human-Skeleton-Model Dissection-kit with 7-tools - including the following: Bent Probe, Dropping Pipette, Probe, Ruler in pocket, Scalpel with 2 Blades - Note blades are in the pocket, Scissors, Tweezers Dissection Tray #2 Small, opaque - Note several supplies are loaded in this tray Pencil, marking Slide - Ground compact bone CS Slide - Hyaline, elastic and fibrocartilage

1 1 1 1

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Discussion and Review
The skeleton is the human body’s foundation. Just like the foundation of a house, the skeleton gives the human body structure and support. Two important tissues make up the human skeleton; (1) bone and (2) cartilage. Each tissue plays a vital role in providing the structure and support for the human body. In addition to support, the skeleton performs several other functions:  The skeleton provides a way to move by creating a system of levers that attach to skeletal muscles. See Figure 1.
Figure 1 – Bones can be thought of as levers, moved by muscle in the body as shown in this drawing.

 

Bones provide a site for the process of blood cell formation called hematopoesis. Bones are also a major storage facility for lipids and minerals (like calcium).

The human skeleton is comprised of a series of bones connected at joints (articulations). These areas are designed to both support and move. Although humans can fatigue these joints to their extreme limits, they are remarkably strong when measuring the amount of force they can withstand.

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Exercise 1: The Chemical Components of Bone
Bones are composed of both organic and inorganic substances. The living tissue of bone contains cells that have specific functions. One type of cell produces a protein called collagen, an organic substance shown in Figure 2. Collagen allows some flexibility and prevents sudden fracturing of the skeletal tissue. Bones are also the reservoirs of calcium. Portions of the bone hold mineral deposits of calcium carbonate and calcium phosphate. These deposits are the inorganic part of bone, which makes them strong.
Figure 2 - Bone matrix showing threadlike fibrils of collagen.

Bones are continually broken down and built again in the human body. The stress that is placed on bones every day from walking, running or even just sitting—due to gravity—allows the bones to maintain their strength. When a bone encounters stress, it is built stronger. On the other hand, when a bone does not encounter stress, the bone is broken down and made weaker. When astronauts travel to and stay on the International Space Station, they are in an environment where they encounter almost no gravity for about 6 months at a time. Because of this, they are required to perform 2 hours of exercise every day in an attempt to maintain the bone and muscle that we maintain on Earth just performing basic tasks of sitting, standing, walking, and running. However, most astronauts still lose bone mass after 6 months of spaceflight. See Figure 3.

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Figure 3 – Astronauts perform strength training exercise while aboard the International Space Station in an attempt to maintain bone mass. Image courtesy of the National Aeronautics and Space Administration.

PROCEDURE
In this activity, two variables, acid and heat, will be tested to observe their effects on the organic structures (collagen/cells) and inorganic structures (minerals) in bone. Day 1: 1. 48 hours before you make your observations, prepare the two chicken leg bones. 2. The easiest way to remove the meat from the bone is to cook the chicken legs. Place them in a pot and cover them with water. Bring the water to a boil and simmer for 45 to 50 minutes. 3. Allow the legs to cool. Remove as much of the meat as you can from each bone. 4. Take one of the bones and place it into a small bowl or plastic container. 5. Pour enough lemon juice into the bowl to cover the bone completely. 6. Place a lid or plastic wrap on the bowl and allow the bone to sit for 48 hours. 7. Preheat the oven to 300oF. 8. Place the second chicken leg bone on a baking sheet and bake in the oven for 40 minutes. 9. Take the tray out of the oven, allow the bone to cool and set it aside for later observation. Turn off the oven.
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Day 3 (48 hours later): 1. Get the dissection tray from the LabPaq. 2. Remove the first chicken leg bone from the lemon juice and get the baked chicken bone. 3. Place the bones on the tray. 4. Observe the color and texture of each bone. Make note of what you see. 5. Gently apply pressure to bend each bone. What happens when you do this? Make note of your observations and answer the questions in the Lab Report. Questions A. Describe the effect that the lemon juice (acid) had on the chicken leg bone. B. Describe the effect that baking (heat) had on the chicken leg bone. C. Rickets is a disease where the bones are not formed completely in children due to a lack of Vitamin D. Does the heated or acid-soaked bone represent a child with rickets? Explain why.

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Exercise 2: The Microscopic Structure of Bone
Bones are formed from two basic types of tissue; compact bone and spongy bone. As the names imply, compact bone is dense and tough while spongy bone, also called cancellous bone, is full of holes and serves as a site for development and storage of materials. Both kinds of tissue play a vital role in bone function. Compact bone consists of columns of support tissues called osteons or the Haversian System. These tissues look like concentric rings from a cut tree when viewed under a microscope. The rings themselves are made of calcified matrix called concentric lamellae. Between the lamellae are small depressions in the matrix called lacunae. The mature bone cells called osteocytes reside inside the lacunae. Each osteon contains a large central canal, also called the Haversian canal, which allows blood vessels and nerves to travel into the bone matrix. Coming off of the central canal are smaller, hair-like canals called canaliculi, which connect the lacunae with the central canal and allow for the delivery of blood and nutrients to the osteocytes. The central canal is fed from the outside of the bone by a series of horizontal perforating canals, which bring in the blood and nutrients from the body. See Figure 4.

Figure 4 – Compact and spongy bone

Items Descriptions 1 Osteon of compact bone Trabeculae of spongy 2 bone Central canal 3 (Haversian canal) 4 Perforating canals Lacunae containing 5 osteocytes 6 Lamellae 7 Canaliculi 8 Osteon 9 Periosteum

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PROCEDURE
1. Obtain the slide of ground compact bone. 2. Place it on the stage of the microscope and scan the slide on low power. 3. Focus on a Haversian system. 4. Switch to medium power and refocus. 5. Switch to high power and sharpen the image with the fine focus if necessary. 6. Observe the structure of the Haversian system. Sketch what is seen into the Lab Report Assistant and identify the following: central canal, lacunae, concentric lamellae, canaliculi and an osteocyte. Questions A. Which part of the Haversian system was the hardest to see on the slide of compact bone? Why? B. Which structures in the compact bone deliver nutrients to the osteocytes? C. Which structures are found inside the central canal?

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Exercise 3: Structure of a Long Bone
Long bones are especially important to mammals because they constitute the mechanism for movement and survival. Long bones are, as the name suggests, longer than they are wide. They have a proximal and a distal end, which are wider than the middle. These ends are called epiphyses (plural) or epiphysis (singular). The epiphyses form the site of joint formation between two bones. The outer covering on the epiphyses is made of hyaline cartilage, which helps reduce friction between bones in a joint. Under the cartilage is a layer of compact bone for support. Beneath the compact bone is spongy bone. The spongy bone in the epiphyses is the site of hematopoesis or blood cell formation. The spongy bone contains red bone marrow, which gives rise to blood cells that are released into the circulatory system. The “long” part of a long bone is the shaft called the diaphysis. The diaphysis is covered by a tough, fibrous membrane called the periosteum (surrounding membrane). The periosteum provides protection for the bone. Moving in from the periosteum, the diaphysis has a ring of compact bone to provide structure and support. Deeper in from the compact bone lies a hollow cavity called the medullary cavity. This cavity is lined with a membrane called the endosteum (inside membrane). The medullary cavity contains yellow bone marrow, which is made of adipose (fat) cells and provides an energy reserve for the body. See Figure 5.
Figure 5 – Diagram of a long bone

Items 1 2 3 4 5 6 7 8

Descriptions Epiphysis Diaphysis Hyaline cartilage Epiphyseal line Spongy bone Medullary cavity Endosteum Periosteum

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PROCEDURE
1. Look at the femur bone of the human skeletal model provided in the LabPaq. See Figure 6.

2. Using Figure 5 or a diagram from the Anatomy and Physiology textbook, identify the external structures of a long bone on the femur model. Use the wax pencil to mark the structures indicated in Figure 5. 3. Observe the photo of the chicken bone femur, cut and shown in Figure 6. 4. Observe the epiphysis. Identify as many of the following structures as possible: articular cartilage, compact bone, spongy bone and bone marrow. Make a sketch of the bone in the Lab Report and label the structures you identified. 5. Observe the section of diaphysis. Identify as many of the following structures as possible: periosteum, compact bone, endosteum and bone marrow. Make a sketch of the diaphysis in the Lab Report and label the structures you identified.

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Figure 6 – Femur of chicken bone, cut longitudinally

Questions A. How does the femur of the skeletal model compare to the diagrams in your textbook or this manual? B. Using your chicken bone, how does the texture of articular cartilage (or hyaline cartilage) compare to that of periosteum? Note: Articular cartilage (made of hyaline cartilage) is found on the ends of the bones. It absorbs compression and allows for smooth movement. C. What is the function of spongy bone? D. What makes compact bone hard?

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Exercise 4: Cartilage
As you saw in Exercise 3: Structure of a Long Bone, cartilage is an important connective tissue that provides support and movement for the body. There are three classifications of cartilage in the body. Cartilage is made by cells called chondrocytes. These cells secrete the fibrous, jelly-like matrix that makes up the non-living portion of cartilage tissue. Hyaline cartilage is the most common type of cartilage found in the skeletal system. It looks like frosted glass when viewed without a microscope. The chondrocytes sit inside depressions called lacunae (same as osteocytes in bone). The matrix is made of collagen fibers. Hyaline cartilage is found at the joints where it provides a smooth, sturdy surface that reduces friction and allows for smooth movement. It is also found in the larynx, trachea, and bronchi in the respiratory system. Elastic cartilage is more fibrous than hyaline cartilage. It is only found in two places, the external ear and the epiglottis in the throat. As the name suggests, it is “elastic” and can stretch easily. See Figure 7. Fibrocartilage looks quite different from hyaline and elastic cartilage. It contains alternating bands of collagen fibers and chondrocytes. It is found in areas where hyaline cartilage joins a tendon or ligament like the intervertebral discs of the spinal column and the knee. Fibrocartilage is very strong and can withstand a lot of pressure.

PROCEDURE:
1. Retrieve the microscope. 2. Select the slides of hyaline cartilage, elastic cartilage and fibrocartilage from the LabPaq. 3. Place the hyaline cartilage slide on the microscope stage. Focus on low power. Switch to medium power. Use the fine focus to sharpen the image. Finally, switch to high power and sharpen the image with the fine focus knob. 4. Sketch a section of the slide in the Lab Report Assistant. Label the following structures: chondrocytes, lacunae and cartilage matrix. 5. Repeat Steps 3 and 4 for elastic cartilage and fibrocartilage.

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Question Using the key, identify each type of cartilage described below: Key: 1. elastic 2. hyaline ____ 6. Most flexible ____ 7. Most abundant ____ 8. Meniscus in the knee ____ 9. Resists compression ____10. The epiglottis 3. fibrocartilage

____ 1. The external ear ____ 2. Between the vertebrae ____ 3. Articular cartilage ____ 4. Found in the trachea ____ 5. Connects ribs to sternum

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Exercise 5: Classification of Bones
Bones are classified by their shape. There are four major shapes of bones; Long, Short, Flat and Irregular. There is also a special classification for the patella (knee cap). This bone is completely encased in ligaments and membranes and is referred to as Sesamoid (sesame seed shaped). Sesamoid bones are a subclassification of short bones. See Figure 8. Long bones are longer than they are wide. They are made of compact bone and are used as levers for movement of major muscles. Short bones are cube shaped and contain more spongy bone than compact bone. Flat bones are generally thin with two thin layers of compact bone sandwiching a layer of spongy bone between. Finally, irregular bones, as the name suggests, have no discernable shape and fall into their own category.

PROCEDURE
1. Prepare a table similar to Data Table 1 below to record observations while performing the experiment.
Data Table 1 – Bone Classification Bone Femur Phalanges Ribs Frontal (skull) Calcaneus (heel) Tibia Carpals (wrist) Patella Long Short Flat Irregular

2. Log onto the Hands on Labs website. Either click on this link or copy and paste it into your browser: https://labpaq.com/ap1 3. Go to “#4: Overview of the Skeletal System”. Click on the link for classification of bones. The Anatomy and Physiology textbook may be used as an additional reference. Read the chart of the different bone classifications. 4. Click on the link for the Skeleton Classification Review on the website. Identify the different classifications of bones on the skeleton diagram. 5. Observe the skeleton model and find the bones listed in the table. 6. Fill in Data Table 1. Classify each bone in the table by making an “x” in the appropriate box.

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Conclusions: What is Osteogenesis Imperfecta and how does it relate to your study of bone tissue?

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The Axial and Appendicular Skeleton
Laszlo Vass, Ed.D. Version 09.1.03
Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will have the opportunity to use a skeletal model to discover how the two regions of the skeleton work together to provide mobility. They will learn about the bones that compose the axial skeleton, pectoral and pelvic girdles, and vertebrae.

© Hands On Labs, Inc. – All rights reserved worldwide.

Objectives
The student will have the opportunity to:  Identify the three bone groups which compose the axial skeleton.  Identify the bones of the pectoral and pelvic girdles and their attached limbs on an articulated skeleton.  Identify the bones of the axial skeleton using an articulated skeleton and your skull as models.  Distinguish between the different types of vertebrae.

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Materials
Materials Student provides LabPaq provides Qty Item Description 1 Internet access to view online materials 1 Anatomy & Physiology Textbook 1 Human-Skeleton-Model

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Discussion and Review
The skeleton is classified into two distinct regions. The axial skeleton consists of the skull, bony thorax (rib cage), and vertebral column. The appendicular skeleton contains the pelvic and pectoral girdles as well as the upper and lower limbs. See Figure 1. In the following exercises, you will explore the various bones of each division and examine how bones fit and relate to each other. You will also use the miniature skeleton in the LabPaq and the Anatomy and Physiology textbook to make these observations.
Figure 1 – The axial skeleton is shown in white and the appendicular skeleton is shown in pink.

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Exercise 1: The Skull
The primary function of the skull is to protect the sense organs and the brain. The bones provide support and attachment points for the various tendons and ligaments. In this activity, the major bones of the skull will be identified. The skull contains 14 facial bones and 8 cranial bones. There are seven other associated bones: six auditory bones (three in each ear) and the hyoid bone. The Cranium The bones of the cranium are pictured in Figure 2. The cranium consists of the frontal bone of the forehead which articulates (creates a joint) posteriorly with the two parietal bones at the coronal suture. The parietal bones are joined superiorly at the sagittal suture. The parietal bones articulate posteriorly with the occipital bone in the back of the skull at the lambdoid suture, completing the posterior wall of the cranium. Laterally, the temporal bone articulates with the parietal bone at the squamous suture. The squamous and coronal sutures are linked by the sphenoparietal suture. Inferior to this suture is the sphenoid bone. The sphenoid and parts of the frontal, temporal and occipital bones make up the floor of the cranium. The sphenoid is unique in that it is a single bone spanning the whole cranium floor but it is only visible on the lateral surface of the skull anterior to the temporal bone and in the back wall of the eye orbit (socket). Finally, the ethmoid bone is a small bone deep inside the eye orbit, behind the bridge of the nose. It forms the medial walls of both eye orbits. The Face The face is constructed of 14 bones: two maxillary, two nasal, two zygomatic, two lacrimal, two palatine, two inferior nasal conchae, the vomer, and the mandible. These bones are labeled in Figure 2. The small nasal bones form the bridge of the nose. Laterally, the maxillae (singular: maxilla) form the floor of each eye orbit and extend inferiorly to form the upper jaw bones. Below each eye orbit are the “cheekbones” known as the zygomatic bones. At the bridge of the nose, lateral to each maxillae, are the lacrimal bones of the eye orbit. Tears drain through a canal in these bones. The lower sets of bones in the nasal cavity are the inferior nasal conchae. The vomer divides the nasal cavity in half. The lower jaw is the mandible. Finally, on the inferior surface of the skull are the palatine bones that construct the roof of the mouth. The palatine bones are not pictured in Figure 2.

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Figure 2 – Bones of the skull: on the left—a frontal view; on the right—a side view.

Item 1 2 3 4 5 6 7

Description Frontal Parietal Sphenoid Temporal Vomer (only seen on frontal view) Nasal Zygomatic

Item 8 9 10 11 12 13

Description Maxilla Inferior nasal concha Mandible Occipital (only seen on side view) Ethmoid (only seen on side view) Lacrimal (only seen on side view)

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PROCEDURE
1. Retrieve the skeleton model from the LabPaq. 2. Find the bones of the cranium and face as listed in Figure 2. Questions A. B. C. D. E. Name the eight bones of the cranium. What function do the cranial bones serve? List the bones that form the eye orbit. Examine the skull on the skeleton model and describe some ways in which the mandible is different from the other bones of the skull. Other than the skull, what are the other two components of the axial skeleton?

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Exercise 2: Skull Markings
In this exercise, you will palpate the major markings and landmarks of the skull. This activity will familiarize you with the important structural features of the skull.
Figure 3 – Palpable areas of the skull

Item 1 2 3

Description Greater wing of the sphenoid Infraorbital foramen Zygomatic bone and arch

Item 4 5 6

Description Temporomandibular joint Mastoid process Mandibular angle

PROCEDURE:
1. Locate and feel (palpate) each of the following areas on your head. Consult Figure 3 if necessary. a. Temporomandibular joint: Place a finger just anterior to your ear canal and open and close your jaws. b. Mastoid process: Place a finger just posterior to your earlobe and apply pressure. You will feel a bump behind the lower jaw; this is the mastoid process. c. Zygomatic bone and arch: Place a finger on your cheek just inferior to the eye. Follow it laterally around to the temporal bone. d. Greater wing of the sphenoid: Place a finger in the notch posterior to the eye orbit and superior to the zygomatic arch. e. Infraorbital foramen: Place a finger on the cheek bone inferior to the eye orbit. Slide the finger medially under the eye and apply pressure.
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f. Mandibular angle: Run a finger posteriorly along the mandible until the “bend” at the back of the jaw is felt; this is the mandibular angle. g. Mandibular symphysis: Feel the indentation on the midline of your chin. This feature is not pictured in Figure 3, but may be seen in Figure 2. h. Nasal bones: Run your finger and thumb along opposite sides of the bridge of your nose until they collapse medially at the inferior end of the bones. Refer to Figure 2. Questions A. Which bone is palpated when touching the forehead? B. What bone is palpated when touching the temple?

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Exercise 3: The Vertebral Column
The vertebral column extends from the skull to the pelvis and is the body’s major support mechanism. It protects the spinal cord and nerves from damage. The vertebrae have a general structure that is modified for specific areas of the body. Superiorly, the cervical vertebrae support the skull and allow the head to move. Moving inferiorly from the cervical vertebrae, the thoracic vertebrae support the torso and bony thorax of the ribs. Inferiorly, the lumbar vertebrae support the lower back. Lumbar vertebrae are more vulnerable to injury than the others because they often take the stress of lifting and moving that is accomplished by the arms. Inferior to the lumbar vertebrae are the fused vertebrae of the sacrum and coccyx. The vertebral column exhibits a curvature to allow for flexibility and movement of the axial skeleton. The cervical, thoracic, and lumbar vertebrae contain intervertebral discs made from fibrocartilage. These discs are designed to cushion the vertebrae and serve as “shock absorbers” for the column.
Figure 4 – Vertebral column

Item 1 2 3

Description Cervical Vertebrae Thoracic vertebrae Lumbar vertebrae

Item 4 5 6

Description Sacral vertebrae Coccyx vertebra Intervertebral disc

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PROCEDURE
1. Observe the vertebral column on the skeleton model from the LabPaq. 2. Go to https://labpaq.com/ap1 and click on “#5: Axial and Appendicular Skeleton.” Use the slides and tutorial for the vertebrae as additional tools for learning. Questions A. B. C. D. E. What are the five categories of vertebrae in your vertebral column? Why are lumbar vertebrae particularly prone to injury? What is an intervertebral disc? What is its function? How are the sacrum and coccyx different from the other vertebrae? What is the overall function of vertebrae?

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Exercise 4: The Bony Thorax
The bony thorax consists of the sternum, ribs, and thoracic vertebrae. The thoracic cage forms a protective barrier for the organs of the thoracic cavity (namely the heart and lungs). The sternum (breastbone) is a flat bone made of three parts. The superior end is the manubrium. The body is inferior to the manubrium, and the xiphoid process is inferior to the body. The ribs are flat bones, which are curved to form the boundary of the thoracic cage. Humans have 12 pairs of ribs. All ribs articulate posteriorly with the thoracic vertebrae. Moving inferiorly from the superior rib, the first seven ribs are called “true” ribs because they all have their own cartilage, which they use to attach to the sternum. The next five pairs are called “false” ribs because they attach indirectly to the sternum via shared cartilage. Finally, the last two pairs of ribs are called “floating” ribs because they have no sternal attachment at all. See Figure 5.
Figure 5 – The bony thorax, with ribs numbered

Item A B C

Description Clavicle Scapula Sternum

Item D E F

Description Ribs Costal cartilage Floating ribs

PROCEDURE 1. Observe the rib cage on the skeleton model from the LabPaq. 2. If an additional reference is needed, refer to your anatomy and physiology textbook. 3. Locate the twelve ribs on your model and identify the true, false, and floating ribs. Questions A. B. C. D. E. What bones make up the bony thorax? What is the function of the bony thorax? What category of bones do the sternum and ribs belong to? Why are ribs 11 and 12 referred to as “floating” ribs? Propose a hypothesis as to why the ribs are attached anteriorly by cartilage.

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Exercise 5: The Appendicular Skeleton
The appendicular skeleton consists of the bones of the upper and lower appendages and the associated structures that attach these bones to the axial skeleton. The appendages are designed for movement. The bones of the appendicular skeleton articulate and move through a series of joints that connect the bones. These joints allow for flexibility between the bones. There are two girdles where the distal appendages are attached to the axial skeleton: the shoulder girdle and the pelvic girdle. The shoulder girdles provide attachment sites for the upper body, and the pelvic girdle provides attachment sites for the lower body. The girdles provide flat areas of bone that allow for multiple attachment sites to muscles. In order to attach the upper body appendages to the axial skeleton, the human body has a right and a left pectoral or shoulder girdle. The shoulder girdle consists of two bones that provide multiple areas for attachment sites of the upper appendages. The anterior bone of the shoulder girdle is the clavicle and the posterior bone is the scapula. See Figure 6. In addition to serving as the attachment point for the upper appendages, the pectoral girdle also serves as an important attachment point for the major muscles of the neck and trunk. From the shoulder girdle, the bones are arranged from the proximal to the distal ends as follows:

Figure 6 – The pectoral or shoulder girdle, anterior view

Item Description 1 2

Clavicle Scapula



Arm: The arm consists of a single bone, the humerus. The humerus is attached proximally to the pectoral girdle at the glenoid cavity of the scapula. The humerus articulates distally with the forearm at the medial trochlea (a spool-like structure) and the lateral capitulum. Forearm: The forearm consists of two bones, the radius and ulna. The radius is the lateral forearm bone and articulates with the humerus proximally at the capitulum and distally with the ulna. The ulna is the medial forearm bone and articulates proximally with the humerus at the trochlea. The ulna also contains the olecranon
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process, which is easily palpated as the “bump” on the posterior of the elbow.  Hand: The hand consists of three groups of bones; the carpals (wrist), metacarpals (palm), and phalanges (fingers).

The lower appendages are attached to the axial skeleton at the sacrum of the pelvic girdle. The sacrum attaches to the pelvis, which is formed by two coxal bones (coxa is Latin for “hip”): one on the right side of the body, and one on the left side. Each coxal bone is the result of the fusion of three bones: the ilium, ischium, and pubis. The coxal bones along with the sacrum and coccyx form the bony pelvis. The ilium is the large, flaring bone that makes up the bulk of the pelvis. The superior spine of the ilium is the iliac crest, which is the top of the hip. See Figure 7.
Figure 7 – The pelvic girdle

Item 1 2 3 4 

Description Sacrum Ilium Ischium Pubis

Item 5 6 7 8

Description Pubic symphysis Coccyx Acetabulum Obturator Foramen

Thigh: The thigh bone is the largest bone in your body: the femur. The femur articulates with the pelvis proximally at the acetabulum (a large rounded socket) which receives the head of the femur. Refer to Figure 7. Distally, the femur articulates with the tibia of the lower leg. The femur forms a joint with the patella (knee cap). The patella is enclosed in a tendon and protects the knee joint anteriorly. Leg: The leg consists of two bones; the tibia and fibula. The larger tibia is medial and proximally forms the knee joint with the femur and patella. The lateral leg bone is the smaller fibula, which lies parallel to the tibia and distally forms the outer lateral “bump” of the ankle.
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

Foot: The foot consists of the tarsal bones (ankle and heel), metatarsals, and phalanges. The talus (ankle) and calcaneus (heel) are the two largest tarsal bones and together they bear the brunt of our body weight. The metatarsals make up the body of the foot. The phalanges are the toe bones.

PROCEDURE
1. Observe your skeleton model from the LabPaq. 2. Identify all of the bones described in the introduction above on the skeletal model. 3. Go to https://labpaq.com/ap1 and click on “#5: Axial and Appendicular Skeleton.” Use the resources for the “Labeled Femur” and other tutorials as additional tools for learning. 4. If an additional reference is needed, refer to your anatomy and physiology textbook. Questions A. B. C. D. E. What is the pelvic girdle? What is its function? What is the pectoral girdle? What is its function? Name the bones of the upper appendages (arm, forearm, and hand). Name the bones of the lower appendages (thigh, leg, and foot). Which of the four categories of bones do MOST of the bones of the appendicular skeleton fit into?

Conclusions Why is it important to relate the structures of the axial and appendicular skeleton to one another?

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Joints and Body Movements
Laszlo Vass, Ed.D. Version 09.1.03

Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will have the opportunity to identify the categories of joints and learn how they work together. With dissection and a human skeleton model, students will identify the relationships among bones, ligaments, tendons, and muscles, and distinguish between structural and functional classification of joints.

© Hands On Labs, Inc. – All rights reserved worldwide.

Objectives
The student will have the opportunity to:  Name and identify the three functional categories of joints.  Name and identify the three structural categories of joints.  Demonstrate and identify various body movements.  Identify the relationship among bones, ligaments, tendons, and muscles.  Identify the types of synovial joints in the body. Time allocation: 2 hours

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Materials
Materials Student provides Label or Box/Bag Qty Item Description 1 Internet access to view online materials Your own body to perform various 1 movements An uncooked chicken wing purchased 1 from the supermarket 1 Human-Skeleton-Model Dissection-kit with 7-tools - including the following: Bent Probe, Dropping Pipette, 1 Probe, Ruler in pocket, Scalpel with 2 Blades - Note blades are in the pocket, Scissors, Tweezers 1 Dissection Tray #2 Small, opaque - Note several supplies are loaded in this tray 1 Apron 1 Gloves packages

LabPaq provides

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Discussion and Review
One of the functions of the skeletal system is to provide movement for the body. In order to accomplish this, segments of the body need to bend, and sometimes bones need to move past each other. Movement is possible because of articulations between our bones, more commonly known as joints. Articulations have two functions. They help hold the various bones of the skeleton together, and they allow movement to occur between segments.
Figure 1 – The knee joint

Joints are classified in two ways; structurally and functionally. The structural classification is based on the presence or absence of connective tissues, cartilage or a joint cavity between the two articulating bones. Structurally, the body contains the following types of joints:    fibrous cartilaginous synovial

The functional classification is based on the amount of movement that is allowed by a particular joint. Functionally, joints are classified as the following types:    synarthroses (immovable) amphiarthroses (slightly moveable) diarthroses (freely movable).

In this exercise, you will have the opportunity to explore the various types of joints in each classification scheme.

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Exercise 1: Identifying Fibrous Joints
Fibrous joints are joined by fibrous tissue. There is no joint cavity present. Most fibrous joints are synarthrotic and allow virtually no movement. Fibrous joints are found in the skull in the form of sutures. These joints have jagged, irregular edges that lock the two joining bones together. There is another category of fibrous joints called syndesmoses and these are found in areas where short, dense ligaments connect the two bones but there is no interlocking between the two bones. The distal joint between the tibia and fibula is a good example of syndesmoses.
Figure 2 – The joints that fit the teeth with the bony mandible are fibrous joints.

PROCEDURE
1. Take out your human skeleton model from the LabPaq. 2. Examine the skull bones of the cranium, in particular the joining of the parietal, frontal, temporal and occipital bones. Look at the sutures between these bones. Questions A. B. As you observe the skull, explain how the structure of the sutures between the cranial bones is related to the overall function of the cranium. Why are synarthroses an important component of fibrous joints?

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Exercise 2: Identifying Cartilaginous Joints
In cartilaginous joints, a sheet or pad of cartilage connects the bone ends. Most cartilaginous joints are slightly movable (amphiarthroses). There are two types of cartilaginous joints in the body: symphyses and synchondroses. Symphyses are the articulations of bones connected by a large flat disc of cartilage. The intervertebral discs and the pubic symphysis of the pelvis are two good examples of symphyses. The second type of cartilaginous joint is the synchondroses. Synchondroses have bony portions united by cartilage. The articulation between the first five ribs and the sternum are examples of synchondroses.
Figure 3 – Portion of pelvic girdle. Arrow points to the pubic symphysis.

PROCEDURE
1. Find a diagram of a skeleton from your textbook or online at the Hands-On Labs web page for this exercise. 2. Identify the location of cartilaginous joints on the diagram as well as on your own body. Questions A. B. Cartilaginous joints exhibit amphiarthroses. Why is this important? Structurally, how are cartilaginous joints similar?

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Exercise 3: Identifying Synovial Joints
Synovial joints are the most familiar articulations. The shoulder, elbow, wrist, hip, knee and ankle are what most people think of when they refer to joints. These are all examples of synovial joints. All synovial joints are freely movable (diarthroses) although the degree to which they can move may vary greatly. Table 1 shows the different types of synovial joints. Synovial joints have common characteristics: 1) First, a two-layered articular capsule (a covering of connective tissue) covers their joint surfaces, which creates a joint cavity. 2) Second, the inner layer of the capsule has a membrane called the synovial membrane. The synovial membrane produces a lubricating fluid called synovial fluid that reduces friction. 3) Third, articular (hyaline) cartilage covers the surfaces of the bones forming the joint. 4) Fourth, ligaments reinforce the capsule and may contain fluid-filled sacs called bursae that help reduce friction where tendons move across bones. 5) Finally, some synovial joints contain fibrocartilage - fibrous cartilage - pads within the capsule.

The “popping” or “cracking” of joints may be caused by escaping gases. The synovial fluid contains gases from the air. When you push on the joint to stretch it, the gases are able to escape, bursting the “bubble” and causing the popping sound. In this case, the synovial fluid must absorb gases once again before it can be “popped” a second time. Other causes of cracking of the joints include movement of either the tendons or ligaments, or the grinding of rough surfaces within the joint.

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Table 1 – Different types of synovial joints.

Type

Pictogram

Movement

Example Intercarpal joints of hand

Plane/ Gliding

Biaxial (flexion, extension, abduction, adduction)

Knee, ankle, elbow (pictured) Hinge Biaxial (flexion, extension, abduction, adduction)

Neck Pivot Uniaxial (rotation) Radiocarpal joints in wrist Condyloid/ Ellipsoidal Biaxial (flexion, extension, abduction, adduction) Thumb joint Saddle Biaxial (flexion, extension, abduction, adduction) Shoulder (pictured) and hip joint

Ball-andsocket

Multiaxial (flexion, extension, abduction, adduction, rotation)

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PROCEDURE
1. Find a diagram of a skeleton in your textbook and retrieve the human skeleton model. 2. Go online to the Hands-On Labs web page (https://labpaq.com/ap1) for this exercise. Click on “#6: Joints,” then click on “Joint Types.” Read the information in this website. 3. Look over Table 1, which describes the different types of synovial joints. 4. Locate each joint on the skeleton diagram and the human skeleton model. 5. Locate each joint on your own body and perform the movement that each joint allows. Observe how the bones move when you perform the joint movements. Questions A. B. C. D. Which type of synovial joint has the least amount of movement? Why are diarthroses important for synovial joints? Which synovial joint is most movable? What are the four structural characteristics that all synovial joints share?

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Exercise 4: Body Movements
PROCEDURE
Joints allow for a variety of movements between bones. In this exercise, students will perform a series of movements to demonstrate the range of motion and flexibility exhibited by the various synovial joints in the body. 1. Perform each of the following movements as you read about them: a. Flexion: This movement decreases the angle of the joint and reduces the distance between the two bones, typically done by hinge joints (knee and elbow). See Figure 4. b. Extension: This movement increases the angle of the joint and the distance between the two bones, typically done by hinge joints (knee and elbow). See Figure 4.
Figure 4 – Flexion (top, red arrow) and extension (bottom, blue arrow)

c. Abduction: The movement of a limb away from the midline or median plane of the body. See Figure 5. d. Adduction: The movement of a limb towards the midline or median plane of the body. See Figure 5.
Figure 5 – Abduction (left, red arrow) and adduction (right, blue arrow)

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e. Rotation: The movement of a bone around its longitudinal axis. Usually performed by ball and socket joints but can be done with the head as the atlas (cervical vertebra 1) moves around the axis (cervical vertebra 2).
Figure 6 – Rotation of the femur

f. Circumduction: This movement combines flexion, extension, abduction, and adduction. Usually seen in ball and socket joints, especially the shoulder. It makes a cone-like circular movement around the axis of the joint.
Figure 7 – Circumduction of the shoulder

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g. Pronation: The moving of the palm of the hand from an anterior or upward position to a downward position. This causes the radius to cross over the ulna. Look closely at your arm as you do this and follow the length of the radius down your forearm to your wrist. h. Supination: The moving of the palm of the hand from a downward position to an upward position (opposite of pronation).
Figure 8 – Pronation (left) and supination (right) of the arm

i. j.

Inversion: The turning of the sole of your foot inward or medially. Eversion: The turning of the sole of your foot outward or laterally.

k. Dorsiflexion: The movement of the ankle joint dorsally. You stand on your heels when you do this. l. Plantarflexion: The movement of the ankle joint downward to point your toes.

Figure 10 – dorsiflexion (left) and plantarflexion (right)

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Questions A. B. Which of the body movements was the most difficult to perform? Why? Hinge joints like the elbow and knee have limited movement. Why are these types of joints more prone to injury? When performing flexion on the arm, the biceps muscle (on the anterior of the arm) contracts. What happens to the triceps muscle (on the posterior of the arm) as this action is performed? Both the shoulder and the hip are ball and socket joints. Why does the shoulder have a greater range of motion than the hip?

C.

D.

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Exercise 5: The Relationship between Bones, Joints, and Muscles
In this exercise, the student will examine how bones, joints and muscles are related both structurally and functionally to one another. A chicken wing will be used as a model to help explain these relationships. Bones are attached to other bones via ligaments. Ligaments are made out of dense connective tissue which is both strong for support and flexible for movement. Ligaments have limited vascularization (blood supply) which makes them slow to heal if they become injured. Muscles are attached to bones via tendons. Tendons are made of dense connective tissue like ligaments but have better vascularization. Tendons pull on the bones, which provide movement as muscles are flexed and extended. Both ligaments and tendons also provide stabilization for synovial joints. This gives the joints the extra support they need to allow for movements between bones.
Figure 11 – Anatomy of a chicken wing

PROCEDURE
1. Retrieve the uncooked chicken wing. 2. Obtain the dissection kit and the dissection tray from the LabPaq. 3. Rinse the chicken wing under running water. Dry it thoroughly with a paper towel and place it onto the dissection tray. 4. Begin by removing the skin from the chicken wing – Steps 5-10. Start at the proximal end where the wing attaches to the body.
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5. Insert the tip of the scissors under the skin and cut along the entire length of the wing to the tip. IMPORTANT: Be careful not to dig into the muscles underneath. 6. The skin will be fatty and slippery. Use a paper towel to pat it dry as you go. 7. Once the cut has been made all the way to the tip, grasp the skin with the tweezers and carefully pull the skin away from the muscle beginning at the proximal end. Notice the fascia, the white connective tissue that holds the skin to the muscle. 8. Use the scalpel or probe to help separate the skin from the fascia. 9. Remove the skin from the upper and lower wing. It is not necessary to remove the skin from the wing tip. Discard the skin into the trash. 10. Make sure to remove the skin from around the joints. 11. Use the blunt probe to gently separate the muscles in the upper wing and lower wing. 12. Look at the second joint. This represents the elbow on our body. Look for tendons attaching the muscles to the bone. The tendons will appear like shiny, white bands of tissue. 13. Grasp one of the tendons with the tweezers and gently pull on it. Does the joint move? 14. Grasp the wing by the shoulder and the wing tip. Bend and straighten the wing several times. 15. Observe what happens to the muscles as the wing joints are flexed and extended. 16. Observe the bones as the chicken wing joints are flexed and extended. As the muscle contracts, the proximal attachments of the muscle to the bone are called the origins. The distal attachments are called the insertions. 17. Look at the shoulder joint. Identify the articular cartilage at the end of the humerus where it attaches to the shoulder. 18. Wash your hands with soap and water, but do not discard the chicken wing until all drawings have been made. 19. Go to the Lab Report and sketch your chicken wing. Label the bones, muscles, and tendons on your sketch (PLEASE NOTE: YOU DO NOT HAVE TO IDENTIFY THE NAMES OF THE SPECIFIC MUSCLES HERE. JUST LABEL WHERE THE MUSCLES ARE IN RELATION TO THE TENDONS AND BONES). 20. Discard the chicken wing in the trash and thoroughly wash the dissection tray and dissection tools with soap and warm water.

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Questions A. B. C. D. E. What effect will the tearing of a tendon have on its corresponding muscle? Why are ligaments harder to heal than tendons? Compare and contrast tendons and ligaments. What is the function of fascia? What effect would the loss of articular cartilage have on a joint, its bones and their corresponding muscles?

Conclusions Explain how skin, bones, and muscles are related to each other. Why is this relationship important to the understanding of the skeletal and muscular systems?

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Organization of Muscle Tissue
Laszlo Vass, Ed.D. Version 09.1.03

Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will have the opportunity to learn about skeletal muscle using a dissection specimen and prepared slides. Students will explore the role of the neuromuscular junction in the gross structure of muscle cells. They will have the opportunity to learn how the functions of actin, myosin, myofibril, myofilament, epimysium, perimysium, endomysium, fascicle, fascia, tendon, and aponeuroses contribute to muscle tissue.

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Objectives

The student will have the opportunity to:  Describe the microscopic and gross structure of skeletal muscle.  Define and explain the function of the following: actin, myosin, myofibril, myofilament, epimysium, perimysium, endomysium, fascicle, fascia, tendon, and aponeuroses.  Describe the structure of a neuromuscular junction and define its role in skeletal muscle function. Time allocation: 2 hours

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Materials
Materials Student provides Label or Box/Bag Qty Item Description 1 Microscope A fresh, uncooked, chicken breast or 1 thigh 1 Internet access to view online materials 1 Paper towel Dissection-kit with 7-tools - including the following: Bent Probe, Dropping Pipette, 1 Probe, Ruler in pocket, Scalpel with 2 Blades - Note blades are in the pocket, Scissors, Tweezers Dissection Tray #2 Small, opaque - Note 1 several supplies are loaded in this tray see below 1 Saline, 1% with 0.01% Thimerosal - 30 mL in Dropper Bottle 1 Slide, blank 1 Slide - Cover Glass - Cover Slip Cube 1 Slide - Cardiac muscle LS 1 Slide - Skeletal muscle w/ neuro 1 Slide - Smooth muscle LS

LabPaq provides

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Discussion and Review
Muscle tissue is organized as a series of cylinders wrapped and bundled together by connective membranes to provide strength and support. These cylinders are often referred to as muscle fibers. Skeletal muscles have several nuclei (multinucleate) and the numerous oval shaped nuclei are visible under the plasma membrane (in muscles the plasma membrane is called the sarcolemma). The cytoplasm of the muscle cell is called the sarcoplasm. Muscle cells have a striped appearance, which is provided by a series of alternating light and dark bands called myofibrils. Inside of the myofibrils are even smaller bands of thread-like fibers called myofilaments. The myofilaments are made up of two contractile proteins – actin and myosin, which slide past each other and enable muscles to contract and extend. The actin and myosin are organized into contractile units called sarcomeres.
Figure 1 – Muscle Fiber Diagram

Item 1 2 3 4 5 6 7 8

Description Fascicle Muscle fiber Sarcolemma Nucleus Sarcoplasm Myofibril Myofilaments Striations

In this exercise, students will examine both the macroscopic and microscopic structure of muscle tissue to understand how skeletal muscle is arranged and organized.

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Exercise 1: Examining Skeletal Muscle Cells
Skeletal muscle is easily viewed microscopically using animal tissue. In this exercise, students will use fresh chicken to examine the structure of skeletal muscle cells.

PROCEDURE
1. Prepare the microscope. 2. Obtain the clean glass slide and cover slip, the dropper bottle of 1% saline solution, the dissection kit, the dissection tray, and the prepared slide of skeletal muscle from the LabPaq. 3. Retrieve the fresh chicken breast or thigh. 4. Wash the chicken under cold water and pat dry with a paper towel. 5. Place the chicken on the dissection tray. 6. Use the tweezers and scalpel to carefully cut away a small, thin section of chicken. The piece should be small enough to fit on a slide. 7. Place the piece of chicken on the slide and add a drop of the 1% saline solution. 8. Using the dissection needle from the LabPaq, pull apart the fibers of the piece of chicken. Tease them apart until it looks like a fluffy mass. 9. Place the cover slip over the piece of chicken on the slide. Place the slide onto the microscope. 10. Begin on low power. Turn the diaphragm so that the light is on the lowest setting possible. Focus the image. 11. Switch to medium power; use the fine focus knob to focus the image. Finally, switch to high power and use the fine focus knob to focus the image. 12. Observe the tissue and look for the banding pattern of the myofibrils. 13. Go to the Lab Report and sketch what you see in the appropriate place in the observations. 14. Remove the chicken tissue slide. Throw away your chicken, clean and dry your slide with soap and water and wash your hands with soap and water (this is very important when working with uncooked chicken). 15. Place the prepared slide of skeletal muscle showing neuromuscular junctions onto the microscope.
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16. Focus the image and view it at low, medium, and high power. 17. Observe the prepared skeletal muscle slide. Sketch what is seen in the Lab Report. Label the sarcolemma and nuclei on your sketch. 18. Go to the LabPaq website at http://www.labpaq.com/ap1 and click on “#7: Organization of Muscle Tissue.” Click on the images of skeletal muscle tissue: “Skeletal Muscle, L.S.” and “Skeletal Muscle, C.S.” Compare your sketches with the photomicrograph of skeletal muscle on the website. Questions A. B. C. What muscular structures cause the striped or banded image seen in the chicken’s muscle tissue? How are muscle cells different from a “typical” cell in the body? What is the sarcolemma?

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Exercise 2: Organization of Skeletal Muscle Cells into Muscles
Muscle fibers are soft, flexible structures that are fragile. In order for muscles to provide the strength and support the body needs, muscle fibers have to be wrapped and bundled. The wrappings and bundles are provided by a series of connective tissue membranes. These connective tissue membranes reinforce the fibers and hold them together to provide strength. See Figure 2.
Figure 2 – Structure of a Skeletal Muscle

Item 1 2 3 4 5 6 7 8      

Description Bone Perimysium Blood vessel Muscle fiber Fascicle Endomysium Epimysium Tendon

Endomysium: Each individual muscle fiber is wrapped in aerolar connective tissue flattened into a sheath. This inner sheath is called the endomysium. Perimysium: Groups of muscle fibers are wrapped in a membrane made from collagen called the perimysium. Fascicles: The bundles of fibers formed by each perimysium are called fascicles. Epimysium: Larger groups of fascicles are then wrapped together by a coarse outer membrane called the epimysium. The epimysium surrounds the whole muscle. Fascia: Further out, each muscle is then connected or bound into functional groups of muscles by dense connective tissue called fascia. Tendons and Aponeuroses: Muscles are then connected to bones by bands of dense connective tissue called tendons or directly to other muscles by sheets of dense connective tissue called aponeuroses.

In this exercise, students will view slides to identify the tissues that group muscle fibers into muscles.

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PROCEDURE
1. Go to the Hands on Labs website. Either click on this link or copy and paste it into your browser: https://labpaq.com/ap1 2. Click on #7: Organization of Muscle Tissue. 3. Open the image labeled “Skeletal Muscle C. S.” 4. Observe the slide. Identify the muscle fibers, endomysium and perimysium. 5. Sketch what you see in the Lab Report. Questions A. B. C. D. Why do muscle fibers need to be wrapped and bundled into groups? Which tissue comprises the muscle wrappings? Why? What is a fascicle? Compare and contrast tendons and aponeuroses.

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Exercise 3: The Neuromuscular Junction
Skeletal muscles are under voluntary control from the nervous system. The body can “inform” the skeletal muscles when, where, and how much to move. This function is possible because each muscle is supplied by impulses from its own dedicated neuron (nerve cell). The connection between the neuron endings (axons) and the muscle cell is the neuromuscular junction. The axons of the neuron branch out into several endings called axon terminals, which then form junctions with individual muscle cells. This allows one neuron to stimulate several muscle cells. The neuron and all of the muscle cells it stimulates are collectively called a motor unit. A motor unit may be composed of a few to thousands of muscle fibers. See Figure 3. The neuron and muscle fibers do not actually touch. There is a fluid-filled space between them called the synaptic cleft. The neuron communicates with the muscle fiber by releasing chemicals called neurotransmitters. These chemicals take the message from the neuron across the synaptic cleft and deliver it to the muscle fiber. This process will be described in more detail in a later activity.
Figure 3 – A motor unit. Note that each type of muscle fiber: Type I, Type IIa and Type IIb, has a motor unit that connects to multiple fibers of the same type.

Item 1 2 A B C

Description Spinal cord Muscle fibers Type I muscle fibers Type IIa muscle fibers Type IIb muscle fibers

PROCEDURE
In this exercise, the student will explore the structure of the neuromuscular junction and relate it to its function. 1. Prepare the microscope. 2. Find the prepared slide of skeletal muscle showing neuromuscular junctions in the LabPaq.
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3. Place the slide on the microscope and focus on the slide. View the slide first on low, medium, and then high power. 4. Observe the slide and find a neuronal fiber from an axon. Follow the axonal fiber to its terminus. 5. The oval shaped structure at the terminus of the fiber is the axon terminal. 6. Go to the Hands on Labs Website. Either click on this link or copy and paste it into the browser: https://labpaq.com/ap1 7. Click on #7: Organization of Muscle Tissue. 8. Click on the image labeled “Skeletal Muscle with Neuromuscular Junction.” 9. Compare your slide with the image on the website. 10. Go to the Lab Report and sketch your slide from the microscope into the appropriate place in the observations. Label the axon, the terminal branches and the muscle fibers. Questions A. B. C. D. How does a motor neuron stimulate a muscle fiber? What happens at the synaptic cleft? What is a motor unit? Why is skeletal muscle called “voluntary” muscle?

Conclusions Why is it important to understand the relationship between nerves and muscles?

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Gross Anatomy of the Muscular System
Laszlo Vass, Ed.D. Version 09.1.03
Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will have the opportunity to identify the major muscles of the human body. They will learn how variables such as size, structure, and shape contribute to the function of major muscles in the human body.

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Objectives
The student will have the opportunity to:  Identify and name the major muscles of the human body.  Explain how muscle actions are related to their location in the body. Time Allocation: Allow 3 hours for this experiment.

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Materials
Materials Student provides Label or Box/Bag Qty Item Description 1 Partner or family member 1 Anatomy and Physiology textbook

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Discussion and Review
Gross anatomy is the study of various structures of the human body, including the study of the muscular system. The muscular system works as a unit with the skeleton to provide structure, support, and locomotion for the body. No single muscle in the body is its own entity; every muscle relies on other muscles to perform a given task. In order to understand muscles, a few terms must be introduced. All muscles are attached to a bone or another muscle through connective tissues such as tendons (muscle connected to bone) or aponeuroses (muscle connected to muscle). The origin of a muscle is its stationary end or attachment, which is the proximal attachment of a muscle. The insertion of a muscle is the movable end, the distal attachment of a muscle. Muscles work through contraction only. However, depending on how muscles are positioned, they may affect flexion and extension of a body part. For example, the biceps brachii originates at the proximal end of the humerus and inserts on the proximal end of the radius. See Figure 1. The action of the muscle is the movement it performs. Flexion is the movement in which the angle between body segments decreases, and extension is the movement of the muscle in which the angle between the segments increases. The biceps brachii performs flexion of the elbow and supination of the forearm. Supination of the forearm is the motion that turns the hand to a forward-facing position that supports the anatomical position. Figure 1 – Two muscles of the arm

Item 1 2

Description Biceps brachii – a flexor Triceps brachii – an extensor

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Muscles work together to perform movements. Muscles that perform a particular movement together are agonists or prime movers. Because prime movers need assistance with movements, muscles called synergists help the prime movers. Fixators are muscles other than the agonists that stabilize the origin of an agonist while it is flexing. Fixators help the action of agonists by reducing or eliminating unnecessary movements that would take away from performing an activity. For example, the large muscles of the back stabilize the neck, shoulder, or torso. See Figure 2. All muscles involved in maintaining posture are fixators. Muscles that oppose or reverse a particular movement are antagonists. Because muscles work together, antagonist muscles can be prime movers also. For example, the triceps brachii, which performs extension of the elbow, is an antagonist to the biceps brachii. The biceps brachii performs flexion of the elbow as a prime movement, but extension of the elbow is also a prime movement. Refer to Figure 1. Figure 2 – The trapezius muscle, highlighted, may act as a fixator for holding the neck stable during flexion of the forearm

Flexing an agonist muscle will cause inhibition of an antagonist muscle. Because some people sit at a desk all day long typing on the computer, they flex their chest muscles for long periods of time, which in turn inhibits their upper back muscles. Because of this repeated flexion/inhibition, these individuals have very tight chest muscles and very weak upper back muscles. This phenomenon causes a severe curvature of the cervical spine, creating a slumped kyphotic posture. In addition, after sitting all day, these individuals also flex their hip muscles for long periods of time, which further inhibits their buttocks muscles. This repeated flexion/inhibition causes weak buttocks and an increased curvature of the lumbar spine – a lordotic posture. Many office workers have kyphotic and/or lordotic postures, which may cause back problems and eventual injury.

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Muscle Names Remembering the names of muscles in the body is a daunting task. There are clues that can help. Muscles have names for the following reasons:  The direction of muscle fibers: Example: The external oblique muscles are on the outside of the lower abdomen, and the fibers run in an oblique manner, as shown in Figure 5. Oblique means neither perpendicular nor parallel.  The location of the muscle: Example: The muscle tibialis anterior is located on the anterior portion of the tibia, as shown in Figure 12.  The shape of the muscle: Example: The muscle orbicularis oris is circular, or orbicular, in shape. This muscle is located around the mouth, as shown in Figure 3.  The action of the muscle: Example: The levator scapulae raises, or levitates, the scapula. This muscle is located on the back of the neck, as shown in Figure 4.  The size of the muscle: Example: The gluteus maximus is larger than the gluteus medius, which is larger than the gluteus minimus. Gluteus refers to the location of the muscles on the posterior thigh, as shown in Figure 11.  The number of origins a muscle has: Example: The biceps brachii has two origins. Biceps means a muscle has “two heads.” The triceps brachii has three origins, or “three heads.” These muscles are located on the arm, and brachii refers to the upper arm. Refer to Figure 1, and see Figures 8 and 9.  The location of the muscles’ origins and insertions: Example: The sternocleidomastoid originates on the sternum (sterno-) and the clavicle (-cleido-) and inserts on the mastoid process of the skull (-mastoid). Refer to Figures 3, 4, and 7. In this experiment, the student will identify the major muscles of the human body through observation and movement of the body. Refer back to the Anatomy and Physiology textbook as needed to see about different body movements including adduction, abduction, supination, pronation, eversion, and inversion.

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Exercise 1: The Muscles of the Head and Neck
Figure 3 - Head and neck muscle anatomy

Item 1 2 3 4 5 6 7 8 9

Description Frontalis Orbicularis oculi Zygomaticus Occipitalis Masseter Sternocleidomastoid Obicularis oris Platysma Trapezius

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Figure 4 – Neck muscles, posterior

Items 1 2 3 4 5 6 7

Description Sternocleidomastoid Splenius capitis Trapezius Levator Scapulae Splenius capitis Supraspinatus Deltoid

PROCEDURE:
1. Prepare a table similar to Data Table 1 below to record observations while performing the experiment.
Data Table 1 – Movement(s) performed by each muscle for Figures 3-4. Muscle Example: Deltoid Frontalis Levator Scapulae Masseter Obicularis oris Occipitalis Orbicularis oculi Platysma Splenius capitis Sternocleidomastoid Supraspinatus Trapezius Zygomaticus Movement(s) Performed Example: Abducts the arm

2. Identify the muscles of the head and neck shown in Figures 3–4. Use the Anatomy and Physiology textbook as another reference for muscles of the head and neck.

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3. Pivot your head side to side. Using Figures 3–4 as a reference, consider the agonists, antagonists, synergists and fixators during this movement. 4. Flex and extend your head. Using Figures 3–4 as a reference, consider the agonists, antagonists, synergists and fixators during this movement. 5. Depress and elevate your mandible. Using Figures 3–4 as a reference, consider the agonists, antagonists, synergists and fixators during this movement. 6. Fill in Data Table 1, listing the movement(s) performed by the muscles learned in Figures 3 and 4. Questions: A. List a muscle shown in Figures 3 and 4 that is a prime mover/agonist for pivoting the head. B. List one prime mover/agonist for extension of the head. C. List one muscle that is the prime mover/agonist for depression of the mandible and list one muscle that is the antagonist for depression of the mandible. D. List one muscle that is a prime mover for smiling. E. List one muscle that raises your eyebrow as if you were questioning what someone said.

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Exercise 2: The Muscles of the Trunk
Figure 5 – Exterior trunk muscles

Item 1 2 3 4 5

Description Pectoralis major Latissimus dorsi Serratus anterior Rectus abdominis (under fascia) External oblique

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Figure 6 –Interior trunk muscles (anterior view)

Item 1 2 3 4 5 6 7

Description Deltoid (cut away) Subscapularis Pectoralis minor Biceps brachii Serratus anterior External intercostal muscles Internal intercostal muscles

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Figure 7 – Neck, thorax, and back muscles

Items 1 2 3 4 5 6 7

Description Sternocleidomastoid Splenius capitis Trapezius Levator Scapulae Splenius capitis Supraspinatus Deltoid

Items 8 9 10 11 12 13

Description Rhomboid minor Teres major Rhomboid major Infraspinatis Serratus posterior Latissimus dorsi

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PROCEDURE:
1. Prepare a table similar to Data Table 2 below to record observations while performing the experiment.
Data Table 2 – Movement(s) performed by each muscle for Figures 5 through 7. Muscle Deltoid External intercostal muscles External oblique Infraspinatis Internal intercostal muscles Latissimus dorsi Pectoralis major Pectoralis minor Rectus abdominis (under fascia) Rhomboid major Rhomboid minor Serratus anterior Serratus posterior Subscapularis Supraspinatus Teres major Trapezius Movement(s) Performed

2. Identify the major muscles of the trunk shown in Figures 5 through 7. Use the Anatomy and Physiology textbook as another reference for muscles of the trunk. NOTE: Use a partner’s help when performing the following actions. 3. With the elbow extended, fully abduct the arm. 4. Adduct the arm. Ask the partner to provide resistance as the arm is adducted. Using Figures 5 through 7 as a reference, consider the agonists, antagonists, synergists and fixators during this movement. 5. Attempt to abduct the arm with the partner providing resistance against the arm. Using Figures 5 through 7 as a reference, consider the agonists, antagonists, synergists and fixators during this movement. 6. Ask the partner to provide resistance on the superior end of the shoulders. Try to elevate the shoulder. Using Figures 5 through 7 as a reference, consider the agonists, antagonists, synergists and fixators during this movement.

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7. Fill in Data Table 2, listing the movement(s) performed by the muscles learned in Figures 5 through 7. Questions A. List one muscle shown in Figures 5 through 7 that is a prime mover/agonist for adducting the arms. B. List one shoulder muscle that abducts the arm. C. Which muscle is the prime mover for shoulder flexion (upper arm moving toward the ear)? D. List one antagonist for shoulder flexion. E. What are the muscles between the ribs called? What do they do?

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Exercise 3: The Muscles of the Upper Body
Figure 8 – Upper arm and chest muscles Item 1 2 3 4 5 6 7 Description Detoid Pectoralis major Coracobrachialis Biceps brachii Brachialis Brachialis Brachioradialis

Figure 9 – Posterior upper arm and back muscles (deep) Item 1 2 3 4 5 6 Description Supraspinatus Deltoid (cut) Infraspinatus Teres major Teres minor Triceps brachii

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Figure 10 – Anterior forearm (left) and posterior forearm (right)

ANTERIOR

POSTERIOR

Item 1 2 3 4 5 6

Description Biceps brachii Pronator teres Brachioradialis Palmaris longus Flexor carpi radialis Flexor carpi ulnaris

Item 1 2 3 4 5 6

Description Triceps brachii Brachioradialis Anconeus Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum communis

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PROCEDURE:
1. Prepare a table similar to Data Table 3 below to record observations while performing the experiment.
Data Table 3 – Movement(s) performed by each muscle for Figures 8–10. Muscle Anconeus Biceps brachii Brachialis Brachioradialis Coracobrachialis Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum communis Flexor carpi radialis Flexor carpi ulnaris Infraspinatus Palmaris longus Pronator teres Teres minor Triceps brachii Movement(s) Performed

2. Identify the major muscles of the upper body shown in Figures 8 through 10. Use the Anatomy and Physiology textbook as another reference for muscles of the upper body. NOTE: Use a partner’s help when performing the following actions. 3. Ask the partner to provide resistance on the forearm as you flex the elbow. Using Figures 8 through 10 as a reference, consider the agonists, antagonists, synergists and fixators during this movement. 4. Flex the elbow completely. Ask the partner to provide resistance against the forearm while you extend the elbow. Using Figures 8 through 10 as a reference, consider the agonists, antagonists, synergists and fixators during these movements. 5. Extend the forearm, flex the wrist and make a fist. Palpate the wrist flexor muscles in the forearm. Using Figures 8 through 10 as a reference, consider the agonists, antagonists, synergists and fixators during these movements. 6. Extend the forearm, pronate the hand, extend the wrist and flare your fingers out. Using Figures 8 through 10 as a reference, consider the agonists, antagonists, synergists and fixators during these movements.

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7. Fill in Data Table 3, listing the movement(s) performed by the muscles learned in Figures 8 through 10. Questions A. List three agonist muscles that flex the elbow. B. List one antagonist for elbow flexion. C. List two muscles that flex the wrist and allow a human to make a fist. D. List two muscles that allow extension of the wrist and flaring of the fingers. E. List one muscle that allows supination of the hand and one muscle that allows pronation of the hand.

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Exercise 4: Muscles of the Lower Body
Figure 11– Anterior thigh (left) and posterior thigh (right)

ANTERIOR

POSTERIOR

Item 1 2 3 4 5 6 7 8 9 10 11

Description Quadratus lumborum Psoas minor (A = Iliopsoas) Psoas major Tensor fascia latae Pectineus Sartorius Adductor longus Gracilis Rectus femoris Vastus lateralis Vastus medialis

Item 1 2 3 4 5 6 7 8

Description Gluteus medius Gluteus minimus Piriformis Gluteus maximus Quadratus femoris Semimembranosus Biceps femoris Semiteninosus

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Figure 12 – Anterior lower leg (left) and posterior lower leg (right)

Item 1 2 3

Description Tibialis anterior Gastrocnemius (cut) Soleus

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PROCEDURE: Use a partner’s help when performing the following actions. 1. Prepare a table similar to Data Table 4 below to record observations while performing the experiment.
Data Table 4 – Movement(s) performed by each muscle for Figures 11–12. Muscle Adductor longus Biceps femoris Gastrocnemius Gluteus maximus Gluteus medius Gluteus minimus Gracilis Pectineus Piriformis Psoas major Psoas minor Quadratus femoris Quadratus lumborum Rectus femoris Sartorius Semimembranosus Semiteninosus Soleus Tensor fascia latae Tibialis anterior Vastus lateralis Vastus medialis Movement(s) Performed

2. Using the diagrams from this manual and your textbook as reference, identify the major muscles of the lower body shown in Figures 11 and 12. Use the Anatomy and Physiology textbook as another reference for muscles of the lower body. 3. Go into a squatting position and palpate the posterior of the hip. Extend the hip and return to an upright position. Using Figures 11 and 12 as a reference, consider the agonists, antagonists, synergists and fixators during this movement. 4. Sit in a chair. Ask the partner to provide resistance on the anterior of your lower leg. Extend the knee. Using Figures 11 and 12 as a reference, consider the agonists, antagonists, synergists and fixators during this movement. 5. Have the partner stand on his toes. The partner may want to stand near a wall and use the wall for balance. Palpate the partner’s calf and follow the muscles down to the heel. Consider which muscles were just palpated. What tendon attaches these muscles to the

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heel? What is the name of the heel bone to which the tendon attaches? 6. Dorsiflex and invert your foot. Palpate the anterior of your tibia. Using Figures 11 and 12 as a reference, consider the agonists, antagonists, synergists and fixators during this movement. 7. Fill in Data Table 4, listing the movement(s) performed by the muscles learned in Figures 11 and 12. Questions A. List one muscle that performed extension of the hip. B. Which muscle extends the knee and flexes the thigh? C. List one muscle that dorsiflexes the foot. D. Which three muscles extend the thigh and flex the knee? E. List three muscles that abduct the leg. Overview Label Figures 13 and 14. Figure 13 – Anterior muscles of the human body

Number 1 2 3 4 5 6 7 8 9 10 11 12 13

Muscle

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Figure 14 – Posterior muscles of the human body

Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Muscle

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Muscle Physiology
Laszlo Vass, Ed.D. Version 09.1.02

Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will learn how twitches, wave summation, treppe, and tetanus develop. They will have the opportunity to create myograms to compare speed of muscle twitches for different muscles. Treppe and wave summation will also be demonstrated through the construction of myograms. Students will test muscle fatigue and learn about isotonic and isometric muscle contractions.

© Hands On Labs, Inc. – All rights reserved worldwide.

Objectives
The student will have the opportunity to:  Explain the differences among a twitch, wave summation, treppe, and tetanus.  Interpret myograms to better understand muscle twitches, treppe, and wave summation.  Describe how a muscle fatigues.  Explain the differences between isometric and isotonic contractions. Time allocation: 2 hours

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Materials
Materials Student provides Label or Box/Bag LabPaq provides Qty Item Description 1 A textbook or other heavy object MS Excel® software (or other 1 spreadsheet program for graphs) 1 Partner or family member Metric Ruler from the Dissection-kit with 7-tools including the following: Bent Probe, Dropping Pipette, Probe, Ruler in 1 pocket, Scalpel with 2 Blades – Note: blades are in the pocket, Scissors, Tweezers 1 Stopwatch-digital

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Discussion and Review
Muscles and nerve tissues are considered excitable because they can produce electrical impulses called action potentials. The electricity is generated by the movement of sodium and potassium ions through specified protein channels in the plasma membrane. When muscles and neurons are at rest, the electrical charge inside the cell is different from the electrical charge outside the cell. The electrical difference can be measured in millivolts and is referred to as the resting membrane potential. Resting membrane potentials differ between cells. Neurons have a resting membrane potential of around 70 mV, and muscle cells have a resting membrane potential of about 85 mV. When a neuron is stimulated by an action potential, the action potential travels through the neuron to the end of the neuron’s axon. There, the neuron releases a type of neurotransmitter, or chemical messenger. These neurotransmitters are released into a gap, called a synapse, between the neuron and the muscle cell. When the neurotransmitters connect with receptors on the sarcolemma (muscle cell membrane), a message is carried to the muscle cell in order to initiate an action potential throughout the muscle cell. See Figure 1.
Figure 1 – Action potential from neuron to muscle tissue

Item 1 2 3 4 5

Description Axon of neuron Neurotransmitters Synapse with neurotransmitter released Neurotransmitter Receptor on sarcolemma Muscle fiber

When acetyl choline connects with the receptors on the sarcolemma, the muscle fibers begin to depolarize, or become less negative. When the membrane potential hits the threshold potential around -55 mV, sodium ion channels open on the sarcolemma. Sodium ions rush into the muscle fiber, causing the sarcolemma to become even more depolarized quickly. The membrane potential can rise to +30 mV or higher at the peak of depolarization. When it reaches near its peak, the sodium ion channels close and potassium ion channels open. Potassium exits the muscle fiber and the membrane potential becomes repolarized (more negative). This repolarization goes beyond the resting membrane potential, called hyperpolarization, but will eventually come back to its resting membrane potential of -70 to 85 mV. See Figure 2.

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Figure 2 – Schematic representation of a skeletal muscle action potential

Item A B C D E

Description Membrane potential Stimulus Depolarization Repolarization Hyperpolarization

Item F G H I

Description Peak Threshold potential Resting potential Time (msec)

This experiment is designed to help better understand muscle physiology. Several different types of muscle contractions will be investigated.

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Exercise 1: Muscle Twitch
Even though muscle fibers are often studied individually to better understand their structure and function, they do not act individually. Several muscle fibers – from tens of muscle fibers to thousands of muscle fibers, are usually stimulated by a single motor neuron. The neuron and the fibers it stimulates are referred to as a motor unit. These fibers may be considered as a muscle “team” that contracts together when they receive stimulation from the neuron. Muscle fibers are either “on” (during a contraction) or “off” (during relaxation). This on or off phenomenon is known as the all or nothing principle. Simply put, muscle fibers are either contracted or relaxed without any intermediate states. The type of muscle contraction a muscle fiber undergoes is determined by the frequency at which the fiber is stimulated by the neuron. If the fiber receives a single action potential from the neuron, the muscle fiber will twitch. A twitch is a single contraction-relaxation cycle. Each twitch has three parts: latent period, contraction phase and relaxation phase. The latent period is the time from the initial stimulation to the start of the muscle contraction. The delay occurs as the neurotransmitter delivers the action potential and engages the myofilaments (actin and myosin) in the muscle fiber. The contraction phase involves the shortening of the fiber and the creation of tension or force within the muscle. The myosin pulls on the actin to shorten the fiber. See Figure 3. The relaxation phase occurs when the neurotransmitter is broken down and the actin and myosin go back to their resting positions. This decreases the tension and force in the muscle. Muscle twitches can be measured and recorded. The information can be presented in a graph called a myogram. Myograms graphically show the relationships between different kinds of muscle contractions and the force they create in a variety of muscles.
Figure 3 – The muscle fiber shortens when the myosin (yellow) pulls on the actin filament (white)

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PROCEDURE
In this exercise, you will have the opportunity to create myograms in order to study three different muscles and contrast the latent period, contraction phase, and relaxation phase of each. Figures 4–6 identify each of the three muscles in the body, and Data Tables 1A–1C include data that will be used to create the myograms.
Figure 4 – Lateral rectus eye muscle (Patrick J. Lynch)

Data Table 1A: Muscle Twitch of the lateral rectus eye muscle

Tension Time (milliseconds) (kilogram-force) 0 0 1 0 2 0 3 10 4 20 5 30 6 40 7 30 8 20 9 10 10 5 11 2 12 0

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Figure 5 – Anterior upper leg muscles. The rectus femoris (2) is pictured.

Item 1 2 3 4

Description Sartorius Rectus femoris Vastus lateralis Vastus medialis

Data Table 1B: Muscle Twitch of the rectus femoris muscle

Time Tension (milliseconds) (kilogram-force) 0 0 3 10 6 20 9 30 12 35 15 40 18 35

Time (milliseconds) 21 24 27 30 33 36 39

Tension (kilogram-force) 30 25 22 15 12 5 0

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Figure 6 – Posterior lower leg muscles. The plantaris (2) is deep to the gastrocnemius (1).

Item 1 2 3

Description Gastrocnemius (cut) Plantaris Soleus

Data Table 1C: Muscle twitch of the plantaris

Time (milliseconds) 0 5 10 15 20 25 30 35 40 45 50

Tension (kilogram-force) 0 5 15 20 25 30 32 36 40 38 35

Time (milliseconds) 55 60 65 70 75 80 85 90 95 100

Tension (kilogram-force) 32 25 22 18 15 12 10 5 3 0

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Study the data for the three muscles in Tables 1A, 1B, and 1C. 1. Make a scatter plot graph in Microsoft Excel® using Data Tables 1A, 1B, and 1C that show the twitch tension timelines of the eye, rectus femoris, and plantaris muscle fibers. For each muscle, connect the dots together in sequence. Refer to the section in the Introduction of this lab manual titled: “Computer Graphing Using Microsoft Excel®” for help with this process. 2. Graph all three sets of data on one graph. Label the three muscles on the graph. Then, graph each muscle set on three separate graphs. Label the latent period, contraction phase and relaxation phase on the three separate graphs. Connect the dots of the scatter plot graph to make a line graph for each muscle. Questions A. What is a muscle twitch? B. According to the graphs, which muscle has the fastest twitch? Why? C. What is the latent period and why does it occur?

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Exercise 2: Treppe—The Staircase Effect
Muscles are slow to move after long periods of rest. When beginning exercise after these long periods of rest, initial muscle contractions are only about half as strong as later contractions, even when the stimuli are of the same strength. As the body “warms up,” this gradual increase in strength leads to a “staircase” increase in tension of the muscle. This is known as treppe. It is believed that treppe results because as the muscle continues to contract and relax, an increase in calcium is available in the sarcoplasm of the muscle cell. The calcium interacts with the troponin on the muscle filaments. Therefore, the calcium aids in exposing additional attachment sites on the actin. The myosin can then connect with the actin to perform a contraction that is stronger for subsequent contractions. In addition, as the muscle heats up, the muscle enzymes work more efficiently and the physical properties of the muscle become more pliable. These are reasons why athletes perform a warm-up period before they begin full-intensity exercise.
Figure 7 – A pictorial representation of treppe

PROCEDURE
In this exercise, the student will have the opportunity to compare the strength of muscle contraction with repetitions over time. 1. Data Table 2 shows muscle tension with increasing time. Observe the values in Data Table 2.

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Data Table 2: Treppe Time Tension (milliseconds) (kilogram-force) 0 0 3 2 6 0 9 4 12 0 15 8 18 0 21 10 24 0 27 12 30 0 33 15 36 0 39 15 42 0 45 15 2. Create a scatter plot graph of the data from Data Table 2. Ensure that you connect the scatter plot dots to create a line graph for better visualization. Plot the time vs. tension in a Microsoft Excel® graph. 3. Use arrows to indicate where each subsequent stimulus occurred on the graph. Questions A. B. Why is treppe an important phenomenon for athletes to understand? Physiologically, what causes treppe to occur?

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Exercise 3: Wave Summation (Temporal Summation)
If a muscle is stimulated repeatedly before it has completely relaxed from the previous stimulus then the contractions are said to be summed or added up. This phenomenon is known as wave or temporal summation. Wave summation results in an increase in tension with each stimulus if the stimuli are timed close enough together before complete relaxation of the muscle fiber. Wave summation occurs because the actin filaments have not fully relaxed when a new stimulus arrives. This releases additional calcium ions into the sarcoplasm exposing more actin-myosin binding sites. The result is increased contractile strength.

PROCEDURE
1. Look over the data in Data Table 3. Data Table 3: Wave Summation Time Tension (milliseconds) (kilogram-force) 0 0 3 5 5 3 7 8 9 5 11 13 13 9 15 20 17 15 19 25 21 0 2. Graph a scatter plot for wave summation of time vs. tension graph using Microsoft Excel®. 3. Use arrows to indicate where the subsequent stimuli occurred on the graph. Questions A. B. Explain why wave summation occurs. Can summation go on infinitely? Why or why not?

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Exercise 4: Tetanus
As the frequency of muscle stimulation increases, the muscle produces peak tension with short cycles of relaxation. See Figure 8. This type of contraction is known as incomplete tetanus. If the frequency of stimulation is so quick that the relaxation phase is completely eliminated, then the resulting contraction is called complete tetanus. Complete tetanus results in a strong, smooth contraction over a period of time. Most of the work our muscles do is accomplished in complete tetanus. The disease called “tetanus” is caused by rod-shaped bacteria that release a toxin when the bacteria die. A tetanus shot may be given to prevent tentanus, and is recommended by the United States Center for Disease Control every ten years. The first symptom of tetanus is “lockjaw” – when the jaw is locked into place by a continuous contraction of the facial muscles. From that point on, muscles throughout the body continue to be affected. The toxin prevents a skeletal muscle neuron from inhibiting the muscle contraction, so the neuron continues to release stimulus, fast enough to produce tetanus.
Figure 8 – A diagram showing muscle stimulation with arrows, and demonstrating muscle twitch, wave summation, incomplete tetanus, and complete tetanus.

Item 1 2 3 4

Description Twitch Wave Summation Incomplete Tetanus Complete Tetanus

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PROCEDURE
1. Look over the data in Data Tables 4A and 4B. Data Table 4A: Incomplete Tetanus Time (milliseconds) 0 3 5 7 9 11 13 15 17 19 21 24 27 30 Tension (kilogram-force) 0 5 3 7 5 9 7 11 9 15 13 15 13 15 Data Table 4B: Complete Tetanus Time (milliseconds) 0 3 5 7 9 11 13 15 17 19 21 24 27 30 Tension (kilogram-force) 0 5 7 9 11 13 15 17 20 20 20 20 10 0

2. Graph the information for incomplete tetanus on a time vs. tension scatter plot graph. Connect the lines of each data point to get a better understanding of the data. 3. Use arrows to indicate where the subsequent stimuli occurred on the graph. 4. Graph the information for complete tetanus on a separate time vs. tension scatter plot graph. Connect the lines of each data point to get a better understanding of the data. 5. Use arrows to indicate the subsequent stimuli on the graph. Questions A. B. What is the difference between complete and incomplete tetanus? Will muscle fatigue occur quicker in complete or incomplete tetanus? Explain the reasoning.

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Exercise 5: Demonstrating Muscle Fatigue
Muscle fibers cannot contract for an indefinite period of time. Eventually the fibers become fatigued and the force of the contractions decreases. Fatigue is brought on by a loss of cellular energy, a decrease in oxygen levels and an accumulation of waste products from metabolism. Fatigue depends on multiple factors, including the intensity of the muscle contraction, the length of the muscle contraction, the physical training levels of the individual, and the type of muscle that is contracting.
Figure 10 – This sprinter may be able to go very fast, but only for a limited amount of time due to muscle fatigue.

Adenosine Triphosphate, ATP, is fuel for all cells of the body, including the muscle cells. As ATP levels drop in the localized muscle area, the body can use energy and oxygen to continue creating ATP so the contraction can be sustained for long periods of time. As long as energy is available from food, the contraction can last until the energy runs out. However, if the muscle contraction is too intense, the oxygen needs of the contracting muscle may exceed the amount that can be delivered to that muscle. In order to supply sufficient ATP to continue the intensity and duration of the muscle contraction, the muscle must utilize a different type of pathway for obtaining ATP. One pathway uses creatine phosphate to produce ATP, but this molecule gets used up very quickly in the muscle and takes about 3 minutes of rest to be replenished again. The other pathway produces lactic acid. Lactic acid may be utilized in the body, but will accumulate in the muscle if the body cannot clear it from the muscle quickly enough. Too much lactic acid causes the muscle fibers to become more acidic. This acidity produces a “burning sensation.” The muscle does not work as efficiently when it is acidic, and therefore, the muscle cannot contract as strongly.

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Many individuals believe that lactic acid can cause sore muscles for days after exercise. Soreness from exercise actually comes from the small tears in the muscle that are in need of repair, as well as intercellular components that spill into the extracellular spaces where these small tears occur. The soreness may last anywhere from 1-5 days depending on the physical fitness of the individual. Scientists have found that the body uses lactic acid for energy and breaks down within 30-60 minutes after very intense exercise.

PROCEDURE
In this exercise, muscle fatigue will be demonstrated by lifting a heavy object. A partner or family member may be required to assist with this exercise. 1. Prepare a table similar to Data Table 5 below to record observations while performing the experiment.
Data Table 5 – Muscle Fatigue Trial 1 2 3 Start Time (seconds) Aching/Burning Feeling Begins Arm Begins to Drop (seconds) Duration (seconds)

2. Obtain the stopwatch from the LabPaq. 3. Retrieve the Anatomy and Physiology textbook (or other heavy textbook). 4. Record a zero “0” in the start time column for Trial 1 into Data Table 5. 5. Stand up and extend an arm straight out in front of you (DO NOT BEND YOUR ELBOW AT ALL) so that the arm is parallel to the floor. 6. Hold your hand out with your palm flat and fingers straight. Place your A&P text in your hand and immediately start the stopwatch. 7. Hold the book straight out in front of you until the arm starts to ache or burn. Ask the partner to record this time into Data Table 5 as “Aching/Burning Feeling Begins.” 8. When the arm begins to drop, ask the partner to record the final time as “Arm Begins to Drop (seconds).” 9. Put down the book and begin the rest period. Rest for one minute. 10. Repeat Steps 4 through 9 twice more, for a total of three trials. Record the data for Trials 2 and 3 next to “2” and “3” in Data Table 5, respectively.
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11. Calculate the total time in seconds required for each trial and record this under “Duration” in Data Table 5. 12. Plot a graph for the total time it took for fatigue to set in for each trial. Label the horizontal axis as “Trial” and the vertical axis as “Time in Seconds.”

Questions A. Explain why muscles get fatigued. B. Which muscle or muscle groups became fatigued with this exercise? C. What causes the burning sensation in a muscle, and how does that sensation affect muscle contraction? D. What might have happened in this exercise if more rest was built into the procedure?

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Exercise 6: Isometric and Isotonic Contractions
There are two major complete tetanic (during tetanus) contractions that muscles can perform. Isometric contractions occur when the muscle length stays relatively constant but there is also tension in the muscle. There is no body movement with isometric contractions because the length of the muscle stays constant. Muscles that maintain posture use these types of contractions.
Figure 11 – Pushing against a wall is an example of an isometric contraction. The muscle length is constant, but there is tension in the muscle.

Isotonic contractions maintain muscle tension while the length of the muscle changes. If you pick up a book and bend your arm to lift it towards you, the tension of the muscle stays relatively the same but the length of the muscle changes quite a bit. Isokinetic contractions are contractions completed at the same speed, but tension and length of the muscle may change throughout the contraction. These types of contractions may only be tested or utilized on special types of machinery. These machines may be used in research or rehabilitation.

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PROCEDURE
In this activity, both isometric and isotonic contractions will be demonstrated. You may need a partner or family member to help you with this exercise. 1. Prepare a table similar to Data Table 6 below to record observations while performing the experiment.
Data Table 6 – Isometric and Isotonic Contractions Trial 1 Tension Length Type of Contraction Trial 2 Trial 3

2. Retrieve the A&P textbook or other heavy textbook. 3. Obtain the ruler with metric measurements. 4. Stand up and extend your arm straight out in front of you so that it is parallel to the floor. DO NOT BEND YOUR ELBOW AT ALL. 5. Palpate (feel) your biceps brachii muscle. Feel the tension of the muscle and measure the length using the ruler. Record this information into Data Table 6, “Trial 1” 6. Hold your hand out and load your arm with the textbook. Palpate the biceps brachii again and notice the degree of muscle tension. Measure the length of the muscle. Record your observations under “Trial 2” in Data Table 6. 7. Gently squeeze the biceps brachii muscle with your opposite hand. Repeatedly flex your arm holding the book six times. Move the textbook at least six inches each time. Palpate the muscle while doing the repetitions, and hold the book at the top of the repetition to measure length again with the ruler. Record your muscle tension and length observations under “Trial 3” in Data Table 6. 8. Fill in the “Type of Contraction” for each trial in Data Table 6. Questions A. B. Which types of muscles do isometric contractions? What happened to the muscle length and tension while performing isotonic contractions? Why do you suppose this occurred?

Conclusions Describe how muscles are designed to receive stimuli. How does this design support their ability to contract?

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Organization of Nervous Tissue
Laszlo Vass, Ed.D. Version 09.1.04

Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will have the opportunity to describe the structure and function of nerves and neurons using prepared slides. They will understand the differences in the structure and function of multipolar, unipolar, and bipolar neurons. Students will explore the role of connective tissues that surround the nerves.

© Hands On Labs, Inc. – All rights reserved worldwide.

Objectives
The student will have the opportunity to:  Describe the structure and function of a multipolar neuron.  Describe the structure and function of unipolar and bipolar neurons.  Describe the functions of the various neuroglia and supporting cells.  Identify the structures of a nerve. Time Allocation: 2 hours

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Materials
Materials Student provides LabPaq provides Label or Box/Bag Qty 1 1 1 1 1 1 1 1 1 Item Description Internet access to view online materials Immersion Oil Microscope with oil immersion lens Slide - Spinal Cord Smear Slide - Teased Nerve Fiber CS Purkinje Cells (website) Pyramidal Cells (website) Dorsal Root Ganglion (website) Neuron (website)

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Discussion and Review
The nervous system is one of two systems (the other being the endocrine), which regulate the activity of other systems in the body. Its primary function is response to the environment of an organism (both internal and external). The ability to respond to or sense a stimulus is critical for survival. In fact, response is one of the defining characteristics of life. The nervous system is divided into two major divisions. The central nervous system includes the brain and the spinal cord. See Figure 1. The main control portion of the system is centered in our brain. However, some signals may be processed in the spinal cord, such as reflexes. The peripheral nervous system includes all of the nerves in the rest of the body. The nervous system relies on the transmission of electrical impulses. Nerves are organized bundles of nervous system cells. These bundles are assigned specific areas of the body from which they receive and transmit information. Nerves carry information back and forth between the peripheral nervous system and the central nervous system. Specialized cells in the nervous system are called neurons, which are designed to carry and transmit electrical impulses generated by both internal and external stimuli. Our five senses—touch, taste, sight, smell, and sound—play the biggest role in providing the nervous system with the information it needs about the environment. Neurons have distinct features. Each neuron has a cell body, or soma. The cell body is where all of the normal metabolic processes occur. Like a normal cell, the neuron cell body has a nucleus and the organelles that are needed for all cell processes. The rough endoplasmic reticulum in a nerve cell is called a Nissl body. These look like large granules in the cell, and are the places in the cell where proteins are synthesized. The cytoskeleton of the nerve cell extends outward to form dendrites and axons. See Figure 2.

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Figure 2 – A Multipolar Neuron

Item 1 2 3 4 5

Description Axon terminals Schwann cells Node of Ranvier Dendrites Soma (cell body)

Item 6 7 8 9

Description Nissl bodies Nucleus Myelin sheath Axon

Dendrites receive incoming signals for the nerve cell. They are usually thin processes that are branched. Refer to Figure 2. Because there are multiple branches, the neuron can receive inputs from many other sources. However, the simplest neuron may only have one dendrite. Dendrites may change size and shape depending on the inputs of neighboring cells. These changes can affect learning and memory. Axons are the branches from the cell body that carry the outgoing signals of the cells to other cells in the body, including other neurons. Like dendrites, a cell may have one axon or many, depending on the function of the neuron. Motor neurons, the neurons that carry signals to the muscles, usually have one long axon. At the end of an axon, extensions of the axon that disperse the signals to the other cells in the body are called the axon terminals. At the axon terminal, there is a small gap between the axon terminal and the cell that is receiving the input from the neuron. This gap is called a synapse. The axon terminals transform the electrical signals into a chemical translation that will send the signal to the other cells by using a chemical called a neurotransmitter that will cross the synapse. See Figure 3.
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Figure 3 – The axon terminal carries chemicals called neurotransmitters that can cross the synapse from a nerve cell to the cell that is receiving the information from the neuron.

Item Description 1 Axon terminal 2 Neurotransmitters 3 Receptors on cell that is receiving input Some messages transferred through neurons need to be sent quickly in the body, while others do not. Speed depends on two properties of the axon, (1) myelination and (2) diameter. Myelin is composed of a fatty substance that supports and insulates the neuron. The insulating myelin allows the electrical signal to travel much more quickly along the axon of the neuron. The electrical signal “jumps” across the Nodes of Ranvier, the non- insulated spaces within the myelin sheath. In addition, the larger the diameter of the axon, the faster the signal travels. Multiple sclerosis causes inflammation of the myelin sheaths around the axons of the nerves in the central nervous system. The body’s own defense system attacks the myelin. Myelin insulates long axons. When the myelin sheath is gone, the nerve cannot effectively send a signal. Neurological symptoms appear with this disease, and can progress to physical and mental disabilities. Currently, there is no known cure for multiple sclerosis. Neurons are classified based on the number of dendrites and axons they possess: multipolar, unipolar, and bipolar. In addition, neurons are fragile and are dependent on a group of supporting cells (collectively) called neuroglia. Neuroglia provide structure for the nervous system, and also communicate to, and support, neurons. Different types of nervous tissue cells will be viewed microscopically throughout the following exercises.
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Exercise 1: The Multipolar Neuron
The most common type of neuron is the multi-polar neuron. Multipolar neurons are named for the many branches, processes and extensions that come off their cell bodies. Figure 2 is an example of a motor neuron. Observe and study Figure 2 and then follow the procedure to study the neuron microscopically.

PROCEDURE
In the following exercise, you will microscopically view multipolar neurons. 1. Retrieve the microscope. 2. Obtain the immersion oil and immersion oil lens for the microscope. 3. Insert the oil immersion lens onto the nose piece of the microscope. 4. Obtain the Spinal Cord Smear slide. 5. Place the slide of the spinal cord smear on the microscope and focus on low power. 6. Following proper microscopic technique, move from low, medium, to high power, and finally up to the oil immersion lens. Observe the spinal cord smear and find a multipolar neuron. 7. Identify the cell body, the nucleus, the large nucleolus, and granular Nissl bodies on the slide. Try to find the axon and differentiate it from the dendrites. 8. Go to the Lab Report Assistant and sketch the cell in the space provided. 9. Now, go to the Hands on Labs website. Either click on this link or copy and paste it into your browser: https://labpaq.com/ap1 10. Click on “#2: Histology” and then click on the Neuron slide. Identify the cell body, the nucleus, the large nucleolus, and the granular Nissl bodies. Try to find the axon and differentiate it from the dendrites. 11. Sketch the cell in the lab report assistant provided. 12. Observe the teased myelinated nerve fiber slide following the same procedure as the spinal cord smear slide. 13. Go back to the Labpaq Anatomy and Physiology website and click on “#10: Organization of Nervous Tissue.” Then click on the photomicrograph of “Teased Myelinated Nerve Fiber Slide.” 14. Using the photomicrograph as a guide, identify the following structures on your own slide: nodes of Ranvier, neurilemma, the axon, Schwann cell nuclei and myelin sheath.
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15. Go to the lab report assistant and sketch your observations in the space provided. Label all of the structures that can be identified. Questions A. B. C. D. What is the function of a neuron? What is the difference between a neuron and a nerve? What gives a multipolar neuron its name? What are the functions of the dendrites and axons?

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Exercise 2: Structures of Selected Neurons
Like multipolar neurons, other neurons are classified according to the number of processes or projections they have extended from their cell bodies. Unipolar neurons have one short process and are most often found in the central nervous system. See Figure 4. Bipolar neurons have two processes, one axon and one dendrite attached to the cell body. See Figure 4. In this exercise, you will compare some of these structural differences found in neurons.
Figure 4 – Bipolar neuron is on the left (1a–6a), and unipolar neuron is on the right (1b–4b).

Item 1a 2a 3a 4a 5a 6a

Description Cilia – sensitive to physical stimuli Dendrite Soma – cell body Terminal buttons of axon Axon Receptor

Item 1b 2b 3b 4b

Description Dendrites Axon Soma – cell body Terminal buttons of axon

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PROCEDURE
1. Go to the LabPaq Anatomy and Physiology website—either click on this link or copy and paste it into your browser https://labpaq.com/ap1 Click on “#10: Organization of Nervous Tissue.” 2. Locate the slide images of Purkinje Cells Slide, Pyramidal Cells Slide, and Dorsal Root Ganglion Slide. 3. Review each of these slide images. 4. Attempt to identify the structures shown in Figure 4. Questions A. B. C. Which slide contained bipolar neurons? Which slide contained unipolar neurons? What was unique about the dorsal root ganglion compared to the other two slides?

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Exercise 3: The Neuroglia and Support Cells
Neurons are specifically designed to transmit electrical impulses. As a result, they are vulnerable and are supported by several structures collectively known as neuroglia or glial cells. The neuroglia provide a variety of services for neurons including protection, support, and immune function. The neuroglia are found in the central nervous system. The peripheral nervous system also has supporting cells, which provide the same kinds of services for neurons outside of the brain and spinal cord. Types of neuroglial cells include: microglia, astrocytes, oligodendrocytes, ependymal cells. Support cells include: Schwann cells and satellite cells. Neuroglial cells:  Microglia – Microglia are immune cells that may phagocytize foreign invaders in the central nervous system when activated. In addition, they may provide protection for the central nervous system.  Astrocytes – Astrocytes are glial cells that branch extensively in the central nervous system. It is estimated that astrocytes make up about half of the cells in the brain. These cells have many roles, including help with ATP synthesis, maintaining homeostasis, and absorbing ions and neurotransmitters. Some astrocytes surround blood vessels to help create a barrier between the blood and the central nervous system. See Figure 5.  Ependymal – Ependymal cells line fluid compartments of the central nervous system to create a selectively permeable epithelial layer. These cells secrete cerebrospinal fluid and beat cilia located on these cells to circulate the cerebrospinal fluid.  Oligodendrocytes – Oligodendrocytes are cells that create the myelin sheath for the neuronal axons in the central nervous system. See Figure 6. Item 1 2 3 Description Oligodendrocyte Nucleus Node of Ranvier

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4

Myelin sheath

Supporting cells  Schwann cells – Schwann cells create the myelin sheath for the neuronal axons in the peripheral nervous system.  Satellite cells – Satellite cells provide support for the nerve cell bodies in the ganglia, a group of nerve cell bodies found in the peripheral nervous system.

PROCEDURE
In this exercise, to learn more about neuroglia or support cells functions, information may be found in the Anatomy and Physiology textbook. 1. Prepare a table similar to Data Table 1 below to record observations while performing the experiment.
Data Table 1 – The Neuroglia and Supporting Cells Cell Function Support and brace neurons. Provide a barrier for selective allowance of nutrients from blood. Provide protection and sense neuron injuries. Can be phagocytic. Ciliated cells found in the cavities of the brain. Help to circulate cerebrospinal fluid. Makes the myelin sheath in the central nervous system. Surround neuron cell bodies with ganglia. Function is mostly unknown. Produces the myelin sheath in the peripheral nervous system. Location (CNS/PNS)

2. Look over Data Table 1, depicting neuroglia and supporting cell functions. 3. Complete the table with the name of the neuroglial cell or supporting cell that matches each function and the location of each cell type.

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Exercise 4: Structure of a Nerve
Nerves are organized bundles of nervous system cells. These bundles are assigned specific areas of the body from which they receive and transmit information. Nerves carry information back and forth between the peripheral nervous system and the central nervous system.

PROCEDURE
1. Observe Figure 7, a diagram of a nerve bundle. 2. Using the Anatomy and Physiology textbook as reference, identify the function of each of the labeled structures. 3. Fill in the functions for the labeled structures in the lab report assistant.
Figure 7 – Diagram of a nerve bundle

Item 1 2 3 4 5 6 7 8 9

Description Epineurium Nerve Blood vessels Axon Myelin sheath Schwann cell Endoneurium Fascicle Perineurium

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Questions A. Describe the functions of the following parts of a nerve: Endoneurium Perineurium B. C. What is a nerve? Differentiate the central nervous system from the peripheral nervous system. Epineurium Fascicle

Conclusions Describe the structure of nervous tissue and relate it to its function.

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Gross Anatomy of the Central Nervous System
Laszlo Vass, Ed.D. Version 09.1.03
Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will have the opportunity to identify the major structures and functions of the brain and spinal cord. Through the dissection of a sheep brain, students will analyze the 12 major cranial nerves and major structures associated with the brain. Then students will draw comparisons between a sheep and a human brain.

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Objectives
The student will have the opportunity to:  Identify and state the functions of the major structures of the brain using diagrams and dissection.  Identify and state the functions of the 12 cranial nerves.  Locate the major functional areas of the brain.  Compare the human brain with that of a sheep.  Describe the structure of the spinal cord and list the functions of major spinal nerves. Estimated Time Required to Complete This Experiment: 4 hours

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Materials
Materials Student provides Label or Box/Bag Qty 1 1 5 1 1 1 Item Description Internet access A&P textbook Paper Towels Self-sealing plastic bag (zip bag), large enough to hold the sheep brain Old shirt to wear during dissection Dissection-kit with 7-tools - including the following: Bent Probe, Dropping Pipet, Probe, Ruler in pocket, Scalpel with 2 Blades - Note blades are in the pocket, Scissors, Tweezers Mask with Earloops (4) in Bag 4" x 7" Assembly Dissection Specimen - Sheep-brain Dissection Tray #2 Small, opaque - Note several supplies are loaded in this tray Gloves packages - 4 pairs Apron

LabPaq provides

1 1 1 1 1

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Discussion and Review
The central nervous system consists of the brain, spinal cord and spinal nerves. This division is constantly receiving information from the peripheral nervous system about the internal and external environment. The brain is the most complex structure. It coordinates human thought, movement, and emotion and sends signals to every other system in the body. The spinal cord is the communication line for the brain. The transmission of messages between the body and the brain rely on the intact spinal cord to communicate the needs of the body to the brain and to communicate the messages from the brain to the body. In this exercise, the student will have the opportunity to explore the structure and function of the brain and spinal cord. These vital organs are amazingly complex and no single structure works alone. The brain is truly the control center of the body and it relies on connections within the brain for communication, and relies on these connections to function correctly. The brain is one of the largest organs in the human body. It weighs around 3 pounds, and has about 100 billion connections. Figure 1 – The brain and the spinal cord make up the central nervous system. This image depicts what the human brain looks like inside a living human.

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The major structural features of the brain are the undulating grooves and ridges that give the brain its surface texture. The shallow grooves are called sulci (sulcus is singular) and the deeper grooves are called fissures. The ridges are called gyri (gyrus is singular). The brain is divided into four main areas: 1) the cerebrum, 2) the diencephalon, 3) the brain stem and 4) the cerebellum. 1) The cerebrum includes the frontal lobe, parietal lobe, temporal lobe, and occipital lobe. See Figure 2. The cerebrum is the most developed portion of the brain. The cerebrum allows the human brain to have emotion, memory, learning, voluntary movement, integration of thought, and perception. See Figure 3 to understand where the brain association and cortical function areas are located on the cerebrum. 2) The diencephalon includes the thalamus, hypothalamus, pituitary, and pineal gland. This portion of the brain is involved in the integration of sensory and motor information, behavioral drives, and hormone secretion. See Figures 4 and 5. 3) The brain stem includes the midbrain, pons, medulla oblongata, and reticular formation. This portion of the brain is involved in eye movement, coordination between the cerebrum and cerebellum, coordination of breathing, control of involuntary functions, arousal, muscle tone, and pain modulation. See Figures 6 and 7. 4) The cerebellum is the integrating center for movement coordination. See Figures 2 through 7.

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Figure 2 – Major landmarks on the lateral view of the exterior human brain

Items for lateral view Item 1 2 3 4 5 Description Central Sulcus Frontal Lobe Temporal Lobe Pons Medulla Oblongata Item 6 7 8 9 Description Spinal Cord Cerebellum Occipital Lobe Parietal Lobe

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Figure 3 - Brain association and cortical function areas

Items for brain association and cortical function areas Item 1 2 3 4 Description Association cortex Motor cortex Somatosensory cortex Association cortex Item 5 6 7 8 Description Visual cortex Wernicke's area Auditory cortex Broca's area

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Figure 4 - Midsagittal view of the human brain

Items for midsagittal view of the human brain Item 1 2 3 4 5 6 Description Spinal cord Cerebellum Medulla oblongata Fourth ventricle Pons Cerebral aqueduct Item 7 8 9 10 11 Description Pineal gland Thalamus Hypothalamus Mammillary body Corpus callosum

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Figure 5 – Some of the major features of the human brain.

Items for some of the major features of the human brain Item 1 2 3 Description Pineal gland Cerebellum Spinal cord Item 4 5 6 Description Medulla oblongata Pons Pituitary gland

Figure 6 – Inferior view of the brain

Items for inferior view of the brain Item 1 2 3 4
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Description Longitudinal fissure Optic chiasma Pons Medulla oblongata
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Item 5 6 7 8

Description Frontal lobe Olfactory bulbs Temporal lobe Cerebellum
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Figure 7 – Frontal coronal section of the human brain

Items for frontal coronal section Item 1 2 3 4 5 6 Description Cerebrum Thalamus Mesencephalon - Midbrain Pons Medulla oblongata Spinal cord

The ventricles of the human brain contain cerebrospinal fluid that courses continuously from the brain to the spinal cord. See Figure 8. A distinguished region on the ventricles called the choroid plexus secretes the cerebrospinal fluid. The cerebrospinal fluid serves to protect the brain from physical impact. This fluid also regulates the chemical extracellular environment for the central nervous system. The brain and spinal cord float in cerebrospinal fluid, which reduces the weight of the brain by almost 30 times. This lighter weight takes pressure off the nerves and blood vessels of the brain.

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Figure 8 – Diagram showing interior ventricles of the brain

Items for diagram showing interior ventricles Item 1 2 3 4 Description Lateral ventricle (right and left sides of brain) Third ventricle Cerebral aqueduct Fourth ventricle

The meninges are membranes that cover the central nervous system. The three layers of meninges include the dura mater, arachnoid, and pia mater. “Dura mater” means “hard mother,” because of the strength of this layer. “Arachnoid” means “spider” because it looks like spider webbing. Pia mater means “gentle mother” because it is the delicate inner covering of the brain. From the ventricles, the cerebrospinal fluid flows into the subarachnoid space – the space between the pia mater and the arachnoid membrane. The dura mater is the final layer of tissue that protects the brain just below the skull. See Figure 9.

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Figure 9 – Pictogram of meninges

Items for pictogram of meninges Item 1 2 3 Description Skin Periosteum Bone Item 4 5 6 Description Dura mater Arachnoid layer Pia mater

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Exercise 1: Structures of the Brain
PROCEDURE:
In this exercise, students will examine the structures of the brain using Figures 2 - 9. Students will have the opportunity to understand the structures well enough to identify the terms on the diagrams in the Lab Report. 1. Label the terms from Figure 2 of the Discussion and Review on this lateral view of the brain below.

2. Label the terms from Figure 4 of the Discussion and Review on this midsagittal view of the brain below.

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3. Label the terms from Figure 6 of the Discussion and Review on this inferior view of the brain below.

4. Label the brain association terms from Figure 3 of the Discussion and Review on this lateral view of the brain below.

5. For additional diagrams, go to the LabPaq website. Either click on the link or copy and paste it into a browser: https://labpaq.com/ap1 Click on the images in The Central Nervous System > Slides and Diagrams > Labeled Human Brain.

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Exercise 2: Sheep Brain Dissection
Mammalian brains have remarkably similar structure among species. Each species will have evolutionary differences that are apparent in structures such as the brain. In this exercise, explore the structure of the sheep brain and compare it to the diagrams of a human brain. While doing this dissection, keep in mind the differences between humans and sheep: what is eaten, where each live, predators or prey, daily activities, and any other differences that come to mind. These clues will help explain some of the structural differences seen in this activity. NOTE: This is a lengthy activity. Some students will not be able to complete this dissection in one session. It is important to protect the brain from drying out and that it is stored in a safe area away from children and pets. Storing the sheep brain between sessions: 1. Wrap the brain in moist paper towels. 2. Place the wrapped brain into a zip bag and seal it. 3. Place the brain in the dissection tray and secure the lid.

PROCEDURE:
In the following exercise, a sheep brain will be dissected. IMPORTANT: Before beginning this exercise, check with the instructor or course syllabus to see which parts of this dissection require completion. 1. Log onto the LabPaq website at https://labpaq.com/ap1 and go to “#11: The Central Nervous System”. Click on the link for the “Labeled Sheep Brain Photos.” Look at photographs of a dissected sheep brain in order to help with the identification of structures in the specimen. It is recommended to review these structures and Figures 1 - 14 before beginning the dissection. 2. Review Figures 2 through 9, and also review images of the central nervous system in the Anatomy and Physiology textbook. Use these diagrams to help compare the human brain structures to that of sheep structures in the specimen. 3. Take out the dissection tray, dissection kit, disposable gloves, goggles, surgical face mask, apron, and preserved sheep brain from the LabPaq. 4. Put on the gloves, goggles, apron, and mask. 5. Remove the sheep brain from its packaging and place it ventral side down onto the dissection tray. See Figure 10.

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Figure 10 – Superior/dorsal view of the sheep brain, ventral side down.

Items for superior/dorsal view of the sheep brain Item 1 2 3 4 Description Parietal lobe Longitudinal fissure Frontal lobe Arachnoid layer and dura mater Item 5 6 7 8 Description Cerebellum Medulla oblongata Occipital lobe Temporal lobe

6. Observe the dura mater. Feel the consistency and make note of its toughness. Using the scalpel, cut through the dura mater along the longitudinal fissure that separates the cerebral hemispheres. Refer to Figure 9. Gently force the hemispheres apart to expose the corpus collosum deep within the longitudinal fissure. See Figure 11.

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Figure 11 – Gently force the hemispheres apart to expose the corpus collosum.

Items for hemispheres Item 1 2 3 Description Cerebellum Corpus callosum Occipital lobe

7. Carefully remove the dura mater from the cerebrum. Take your time with this and try not to go deep to prevent damaging the delicate cerebral cortex. Expose the entire cerebrum. See Figure 12. Figure 12 – Meninges, superior/dorsal view of the sheep brain, ventral side down. Items for superior/dorsal view of the sheep brain Item 1 2 3 4 Description Transverse fissure Meninges intact Longitudinal fissure Meninges removed

8. Observe the convolutions on the surface of the cerebral hemispheres. Identify the arachnoid layer that appears as a delicate almost cotton-like membrane that spans across the fissures along the surface of the brain. The innermost membrane layer is called the pia mater. If observed very closely, this membrane will follow the contours of the fissures along the surface of the brain.

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9. Turn the brain so that the ventral side is now facing upward. Note the oval-shaped olfactory bulbs on the anterior portion of the frontal lobes. Compare the size of the olfactory bulbs on the sheep brain with that of a human brain. The sheep bulbs are shown in Figure 13, and refer to Figure 6 to see the human olfactory bulbs. Figure 13 – Ventral side is facing upward, sheep brain pictured was cut in half. Picture by Jamie Bresnahan

Items for ventral side of sheep brain Item 1 2 3 4 5 6 Description Olfactory bulb Frontal lobe Optic chiasma Optic nerve Optic tract Infundibulum Item 7 8 9 10 11 Description Mammillary body Cerebral peduncle Oculomotor nerve Pons Medulla oblongata

10. Posterior to the olfactory bulbs you will notice the “X” shaped optic chiasma formed by the crossing over of the right and left optic nerve. Identify the optic nerves, optic chiasma and optic tracts. Refer to Figure 13. 11. Posterior to the optic chiasma are two structures protruding from the hypothalamus, the infundibulum – pituitary stalk/stem – and mammillary body. 12. Moving posteriorly, the cerebral peduncles are immediately below the mammillary body on a region called the midbrain. The cerebral peduncles provide fiber tracts that connect the cerebrum and the medulla. The large oculomotor nerve and tiny trochlear nerve endings may be seen coming off the midbrain region. NOTE: Do not worry if the nerves cannot be seen. Identify their location using Figure 14 or the Anatomy and Physiology textbook.
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13. Moving posteriorly from the midbrain, identify the pons and then the medulla oblongata, which are a part of the hindbrain. 14. The identification of cranial nerves can be a difficult exercise to complete. Specimens vary greatly, but at least a couple of cranial nerves should be apparent. See Figure 14, or use the diagram on the website as a guide. To find the diagram on the website, click on the link for “Sheep Cranial Nerves” in “The Central Nervous System.” Try to identify as many of the cranial nerves as possible on the specimen. Please Note: It is very rare that a single sheep brain will have all or even most of these cranial nerves intact after dissection. Do the best dissection possible, but do not worry about how many can be seen on the specimen. Figure 14 – The 12 Cranial Nerves, pictogram of a human brain

Items for the 12 cranial nerves Item 1 2 3 4 5 6 Description Olfactory nerve (I) Optic nerve (II) Oculomotor nerve (III) Trochlear nerve (IV) Trigeminal nerve (V) Abducent nerve (VI) Item 7 8 9 10 11 12 Description Facial nerve (VII) Auditory nerve (VIII) Glossopharyngeal nerve (IX) Vagus nerve (X) Accessory nerve (XI) Hypoglossal nerve (XII)

15. Moving posteriorly, identify the cerebellum on the specimen. Notice that the sheep cerebellum is not divided longitudinally like the human cerebellum. In terms of
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relative size, is the human or sheep cerebellum larger compared to the rest of each respective brain? Why? (Think about the functions of the cerebellum and how sheep and humans perform those functions differently). 16. Place the brain ventral side down on the dissecting tray. Use the scalpel to cut through the brain tissue following the longitudinal fissure starting from the anterior and moving to the posterior. Cut through the corpus collosum, midbrain, cerebellum and brain stem straight back until the right and left hemispheres of the brain are separated. 17. Take one of the hemispheres and turn it so that the internal brain structures are facing upward. Identify the thalamus, corpus collosum, third ventricle, fourth ventricle, cerebellum, cerebral aqueduct, and brain stem. Refer to Figure 4 for a human brain comparison. 18. Review all of the structures of the sheep brain. Answer the questions for this section (It is recommended that this is done before the brain is discarded so the specimen may be used as a reference). 19. After answering the questions, wrap the brain hemispheres in a paper towel and place them in a zip bag. The brain may be disposed of in the trash. Wash all of the equipment thoroughly with soap and water and dry the dissection instruments before storing them. Questions: A. Which of the four major areas of the brain (cerebrum, diencephalon, cerebellum and brain stem) was obviously much larger in the human brain diagram than in the sheep brain? Why do these structures differ so dramatically? What is the significance of the size difference in the olfactory bulbs between humans and sheep? The human cerebellum is split in half while the sheep cerebellum is one mass. Why does this structural difference exist? What is the significance in the size difference between the sheep and human brain stems? What is the function of the third ventricle, fourth ventricle, cerebellum, and brain stem? In your own words, explain how (if) this exercise helped you better understand brain anatomy.

B. C. D. E. F.

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Exercise 3: The Cranial Nerves
The brain has twelve pairs of cranial nerves that remain in direct contact with the areas of the body and that provide it with vital information. Most cranial nerves are centered in the head and neck. A notable exception is the Vagus nerve, which has branches that extend to the abdomen. Cranial nerves are numbered with Roman numerals, and their names often give clues about the areas they serve and their function(s).

PROCEDURE:
1. Prepare a table similar to Data Table 1 below to record observations while performing the experiment. 2. Review Figure 14. 3. Using the Anatomy and Physiology textbook as a reference, identify the function of each cranial nerve. 4. Fill in Data Table 1. Data Table 1: Cranial Nerves Cranial Nerve I. II. III. IV. V. VI. VII. VIII. IX. X. XI. XII. Questions: A. Which cranial nerves are involved in the following activities? Smelling a flower: Tasting freshly baked cookies: Shrugging shoulders: Slowing heart rate: Function Is it Sensory/Motor/Both?

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Exercise 4: The Spinal Cord and Spinal Nerves
The relaying of information from the brain to the body relies on the largest nerve bundle transport system in the body, the spinal cord. The spinal cord and its associated nerves allow us to communicate movements, processes and actions between the brain and the body. The spinal cord is inherently fragile because it is made of nerves. Our body protects it by encasing it in vertebral bone. Figure 15 –Cross-sectional view of the spinal cord

Items for cross-sectional view of the spinal cord Item 1 2 3 4 5 6 7 8 Description Lateral funiculus Central canal Posterior funiculus Posterior horn Subdural cavity Dorsal root Dorsal root ganglion Spinal nerve Item 9 10 11 12 13 14 15 16 Description Ventral root Lateral horn Anterior funiculus Subarachnoid cavity Anterior horn Dura mater Arachnoid membrane Pia mater

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PROCEDURE
In the following exercise, material covered in Figure 15 will be examined. 1. Become familiar with the material covered in Figure 15. 2. Label the structures indicated on the diagram in question A. Questions: A. Label the terms on this cross-sectional view of the spinal cord. Refer to Figure 15 as a guide.

B. Use information from the Anatomy and Physiology textbook to fill in the table with the names of the major spinal nerves that serve the areas indicated. Nerve Area of the body served Head, neck, shoulders (plexus only) Diaphragm Posterior thigh Anterior thigh Arm muscles Anterior forearm Abdominal wall Medial side of the hand Leg and foot

C. Use the information from the Anatomy and Physiology textbook to define a plexus.

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Reflex and Sensory Physiology
Laszlo Vass, Ed.D. Version 09.1.03

Review the safety materials and wear goggles when working with chemicals. Read the entire exercise before you begin. Take time to organize the materials you will need and set aside a safe workspace in which to complete the exercise.

Experiment Summary Students will have the opportunity to demonstrate several somatic and autonomic reflexes including taste, smell, vision, hearing, and balance. They will understand the structure of the eye and how after images and blind spots occur.

© Hands On Labs, Inc. – All rights reserved worldwide.

Objectives
The student will have the opportunity to:  Define a reflex and reflex arc.  Describe, perform, and discuss several somatic and autonomic reflex exercises in the lab.  Describe the relationship between taste and smell.  Describe what a blind spot is and why we have afterimages.  Discuss the structure of the eye.  Describe the relationship between hearing and balance. Time allocation: Estimated time to complete this experiment, 5 hours

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Materials
Materials Student provides Label or Box/Bag Qty 1 1 2 1 1 4 5 1 1 1 1 1 1 1 1 1 1 1 1 1 Item Description Meter stick or measuring tape 3x5-inch note card Cotton balls Salt Lemon juice Paper cups Cotton swabs Sugar Coffee Sharp pencil A ticking clock, watch or kitchen timer Handkerchief or towel to use as a blind fold Tongue depressor (craft stick/ice cream stick will work). A partner Sturdy table that will hold the weight of a person Anatomy and Physiology Textbook Measuring cup Spoon Paper towels Dissection-kit with 7-tools - including the following: Bent Probe, Dropping Pipette, Probe, Ruler in pocket, Scalpel with 2 Blades - Note blades are in the pocket, Scissors, Tweezers Mask with Ear loops (4) in Bag 4" x 7" Assembly Pipette, Empty Short Stem - Taste Tests (4) Dissection Specimen - Cow-eye Dissection Tray #2 Small, opaque - Note several supplies are loaded in this tray Gloves packages - 4 pairs Pencil, marking Reflex hammer Tuning-fork-1000-Hz Flashlight Goggles

LabPaq provides

1 1 1 1 1 1 1 1 1 1

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Discussion and Review
The human body relies on senses and reflexes every day. They are critical for protection and maintenance of body functions. Senses relay important messages to the body for normal function. Reflexive actions send signals to the body very quickly, in response to external stimuli. Our senses inform the brain and the body of what is happening in the external environment. A reflex is a rapid, involuntary motor response to stimuli. Reflexes cause a reaction without conscious thought. For example, if someone quickly flashes a hand in front of a person’s face, that person is likely to close the eyes and pull his head away from the hand in order to protect his eyes from being hit. All reflexes involve neural pathways called reflex arcs. A reflex arc is a communication pattern that initiates an action in the body. 1) Reflex arcs begin with a stimulus, a change of the internal or external environment that is detected by the body. 2) The stimulus causes sensors to relay information through an afferent (sensory) neuron to an integration center. 3) The integration center is usually in the spinal cord, but in some cases may be in the brain (supraspinal reflexes). The integration center interprets the message. 4) The integration center then sends a message through an efferent (motor) neuron to the muscles. 5) The muscles (effectors) respond with an action.
Figure 1 – Diagram of a Reflex Arc

Item 1 2 3 4 5 6 7 8

Description Spinal cord Cell body of motor neuron Motor neuron Skin receptor (responding to pin) Effector muscle Motor neuron Cell body of motor neuron Interneuron (central processing)

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Reflexes can be categorized in two major ways. First, Autonomic reflexes are regulated by the autonomic nervous system and involve reflexes that do not include human conscious control. These reflexes control processes in the body such as digestion, blood pressure, salivation, and sweating. Second, humans have somatic reflexes, which are controlled by the somatic nervous system and involve the stimulation of skeletal muscles. An example of a somatic reflex would be rapidly withdrawing your hand after accidentally touching a hot stove. Senses inform our brain about the external environment and reflexes cause quick, necessary reactions in response to the sensory information. In the following exercises, using the stimuli and physiology for four of your five senses (taste, smell, sight and hearing), the functions of human senses and reflexes will be observed.

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Exercise 1: Stretch Reflexes
The testing of reflexes is a very important diagnostic tool that physicians use to determine the condition of the nervous system. One of the most important somatic reflexes to test is the stretch reflex. Stretch reflexes help maintain posture, balance and locomotion. These reflexes involve the stimulation of a tendon to initiate a muscle stretch. In this activity, two stretch reflexes will be tested. The patellar (knee jerk) reflex and the Achilles (ankle jerk) reflex.
Figure 2 – Patellar (Knee Jerk) Reflex

Item 1 2 3 4 5 6

Description Stimulus on Patellar tendon Afferent nerve (sensory) Spinal cord Efferent nerve (motor) Quadriceps muscle group Leg kicks out

PROCEDURE:
1. A partner or family member is required to complete this exercise. One person is the subject being tested, the other is the tester. You can choose to be either the subject or the tester. 2. Retrieve the reflex hammer from the Anatomy and Physiology LabPaq. 3. The subject being tested should sit on the edge of a table. The legs should be dangling freely and not touching the floor.

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4. The patellar ligament is located about one finger width below the patella (knee cap). The person who is the tester should tap the subject’s patellar ligament with the flat (not pointy) end of the reflex hammer to initiate the reflex. This may have to be repeated several times to get this to work. A couple of things to keep in mind:  The subject’s legs should be relaxed and dangling freely. Do not tighten up the leg muscles.  Make sure to tap the ligament BELOW the patella, not the patella itself (ouch!). 5. Test both knees. 6. Answer Questions A and B for this exercise. 7. Test the effect of a mental distraction on this reflex. Have the subject add up a column of three-digit numbers (ex. 123 + 245+ 367 + 491) while you test the reflex again. 8. Answer Questions C and D. 9. Test the effect of exercise on the reflex by having the subject run in place or up and down some stairs until he or she becomes very fatigued (the subject must be very fatigued to ensure the exercise will work properly). 10. Ask the subject to sit on the edge of the table immediately after exercising and test the reflex again. 11. Answer Questions E and F. 12. Have the subject remove his shoes and socks. Test the Achilles reflex by holding his foot in a hand. Have the subject dorsiflex his foot slightly, then sharply tap the calcaneal (Achilles) tendon (above the heel) with the flat edge of the reflex hammer. You may have to practice this several times to get a result. 13. Answer Questions G and H. Questions: A. B. C. D. Which muscles contracted with the patellar reflex? Which nerves carried the stimulus to the spinal cord? Is the patellar reflex response during mental distraction greater than or less than the response without mental distraction? What can be concluded about the effect of mental distraction on reflex activity?
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E. F. G. H.

Is the patellar reflex more or less vigorous after exercise? Did muscle function or nervous system activity cause the changes observed after exercise? Explain. Describe the result of the Achilles tendon test. Does the gastrocnemius muscle normally do what you observed with this test? (Think about the function of this muscle).

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Exercise 2: The Crossed Extensor Reflex
The crossed extensor reflex may also be called a withdrawal reflex. When sudden pain occurs in one limb, the flexors activate in the limb that is withdrawn and the extensors relax in that same limb. In the other limb, the opposite occurs, where the extensors are active and the flexors relax. For example, when a person steps on a tack with his left foot, the hamstrings of the left foot contracts, while the quadriceps are relaxed. The leg moves upward. Since the right leg is needed to hold the person upright, the quadriceps on the right leg contract, while the hamstrings relax, and all of the person’s weight is placed on the right leg.
Figure 3 – Example of crossed extensor reflex

Item 1 2 3 4 5 6 7

Description Stimulus (tack) Afferent neuron To brain Spinal cord Efferent neurons Quadriceps muscles Hamstring muscles

PROCEDURE:
1. Find a sharp pencil. 2. Place a blindfold over the subject’s eyes. 3. Have the subject sit at a table with his or her arms out in front and palms up.

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4. Suddenly prick the subject’s index finger with the pencil. Observe what happens. Questions: A. B. What happened when you pricked the subject’s finger? Did this reflex seem to be slower than the other reflexes observed? Why or why not?

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Exercise 3: Cranial Nerve Reflexes
Certain reflexes in the body are regulated by the twelve cranial nerves (see the Anatomy and Physiology textbook for a list of the nerves and their functions). In this exercise, you will test the corneal reflex (controlled by trigeminal cranial nerve V) and the gag reflex (controlled by the accessory nerve cranial nerve IX and the hypoglossal nerve, cranial nerve X). See Figure 4.
Figure 4 – The 12 Cranial Nerves, pictogram of a human brain

Item 1 2 3 4 5 6 7 8 9 10 11 12

Description Olfactory nerve (I) Optic nerve (II) Oculomotor nerve (III) Trochlear nerve (IV) Trigeminal nerve (V) Abducent nerve (VI) Facial nerve (VII) Auditory nerve (VIII) Glossopharyngeal nerve (IX) Vagus nerve (X) Accessory nerve (XI) Hypoglossal nerve (XII)

PROCEDURE:
In the following exercises, you will test the blink reflex and the gag reflex on another person. A partner will be needed for the following exercise. 1. Retrieve a cotton swab. 2. Stand to one side of the subject and have him look away from you at an opposite wall. 3. Wait a few seconds and then quickly but gently touch the cornea of the subject’s eye with the cotton swab. 4. Answer Questions A and B. 5. Retrieve a tongue depressor.
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6. Have the subject open his mouth wide. 7. Use the tongue depressor to stroke the oral mucosa on either side of the uvula in the back of the throat. 8. Answer Question C. Questions: A. B. C. Describe what happened when the subject’s cornea was touched. What is the function of the corneal reflex? Why do humans have a gag reflex?

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Exercise 4: Cow Eye Dissection
The eye is a hollow structure surrounded by connective tissue called the sclera. The sclera is covered by a clear mucous membrane called the conjunctiva. The eyeball is divided into two compartments: the anterior chamber and the vitreous chamber. The chambers are separated by the lens. When light enters the eye, it first passes through the cornea, which is the outer layer of the eye and a continuation of the sclera. The anterior chamber contains a liquid called the aqueous humor, a fluid secreted by the ciliary epithelium that supports the lens. A circular disc just below the aqueous humor is called the iris. The iris is attached to muscles that dilate or constrict the pupil, an opening in the middle of the iris. Therefore, the iris controls the amount of light that enters the eye. See Figure 5.
Figure 5 – Diagram of a human eye

Item 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Description Iris Pupil Cornea Anterior Chamber (Aqueous Humor) Ciliary Muscle (Ciliary Body) Suspensory Ligament Lens Fovea Renal Blood Vessels Optic Nerve Optic Disc Sclera Choroid Retina Vitreous Chamber (Contains Vitreous Humor)

After the light goes through the pupil, it passes through the lens, which uses the ciliary muscles to change the shape of the lens. The ciliary muscles are attached to the lens by suspensory ligaments. The shape of the lens determines the focus of the light and image on the retina. The retina is the layer in the posterior portion of the eyeball that contains photoreceptors. Once the image is received by the photoreceptors, signals are sent to the brain for interpretation via the optic nerve. The place where the optic nerve, arteries, and veins exit the eyeball is called the optic disc. Since there are no photoreceptors on the optic disc, this is called the “blind spot.”

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The vitreous humor is the fluid contained in the vitreous chamber, and helps to uphold the shape of the eyeball. In the middle of the sclera and the retina, the choroid coat is a specialized surface that reflects light entering the eye and is found in animals that live in low light conditions such as cows and sheep. The choroid coat in humans provides oxygen and nourishment to the outer layers of the retina. Refer to Figure 5 for a diagram of all the main structures of the eye. Before reflex exercises are performed on the eye, the structure of the eyeball will be explored by dissecting a preserved cow eye. All mammalian eyes have roughly the same structure. Cow eyes, while larger than human eyes, make a good specimen for study because of the easily visible structures. If for any reason you need to interrupt this exercise, wrap the cow eye in some wet paper towels and place it on the dissecting tray. Cover the tray with its lid and secure tightly. The specimen may remain this way for as long as a few days.

PROCEDURE:
1. Get out the dissection tray, dissection kit, preserved cow eye, a pair of disposable gloves, goggles and a face mask from the LabPaq. 2. Go to the Hands on Labs Website. Either click on this link or copy and paste it into the browser: https://labpaq.com/ap1 3. Go to “Reflex and Sensory Physiology”. Click on the “Dissected Cow Eye” link to see photographs of a dissected sheep eye with labels of structures. The sheep eye is very similar to the cow eye. Use these photographs to help identify structures on the cow eye. It is recommended that these structures are identified before beginning the dissection. 4. Put on the disposable gloves, goggles and mask. 5. Open the preserved cow eye, place it on the dissection tray and discard the packaging. 6. Examine the external surface of the eye. Note the thick layer of adipose tissue (fat) that surrounds the eye. 7. Identify the cut end of the large optic nerve (cranial nerve II) on the posterior aspect of the eye as it leaves the eyeball. Refer to Figure 5. 8. Notice the remnants of extrinsic eye muscles (usually brown in appearance), the conjunctiva, the sclera and the gray-cloudy cornea which is transparent in a living eye but becomes clouded when preserved. 9. Use the scalpel and tweezers to trim away most of the fat and connective tissue. Be
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sure to leave the optic nerve intact. 10. Turn the eye so that the cornea is facing downward. Hold the eye firmly in place with one hand. Use the scalpel in your other hand to carefully make an incision into the sclera about 6 mm or ¼ inch above the edge of the cornea on the side of the eyeball. NOTE: The sclera is very tough tissue. Apply pressure to get the scalpel to penetrate the surface. 11. Once the incision into the sclera has been made, turn the eyeball on its side and use scissors to cut around the edge of the cornea all the way around the circumference of the eye. While cutting, stay parallel to the edge of the cornea. 12. Lay the eye on the tray with the cornea facing upward. Use the tweezers to carefully remove the cut anterior portion of the eye away from the posterior portion. 13. Examine the anterior part of the eye. structures: Refer to Figure 5 and identify the following

Ciliary Body: Black pigmented body that looks like a halo circling the lens. It also has the appearance of gills found on the inferior portion of a mushroom. Lens: The hard, biconvex structure found within the ciliary body. It appears clouded or opaque in preserved specimens but is clear in the living eye. Suspensory ligament: A ring of delicate fibers that attaches the lens to the ciliary body. Remove this ligament and the lens to identify the next few structures. Iris: Anterior portion of the ciliary body. It forms the colored portion of our eyes. In cows it is usually a dark brown or black pigment. The center hole in the iris is the pupil. Cornea: The clear, anterior portion of the sclera. It is clear in the living eye but clouded in the preserved specimen. 14. Examine the posterior portion of the eyeball. Remove the jelly-like vitreous humor and refer to Figure 5 to help identify the following structures: Retina: This is the thin membrane covering the posterior surface of the eyeball. It appears yellowish-white and may be pulled away from portions of the posterior wall. The retina contains the photoreceptors that process light coming into the eye. Choroid coat: This is a thin membrane along with the retina but appears iridescent like a pearl or oyster shell. 15. Review all of the structures of the cow eye. Use the images on the website and Figure 5 to help identify specific structures. Answer the questions in the Lab Report.

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16. When finished, wrap the cow eye structures in paper towel and place them into a small sandwich bag. Dispose of the bag in the trash. 17. Wash the dissection tray and dissection instruments with soap and water and be sure to dry them thoroughly with paper towels. Questions: A. B. C. What is the function of the retina? What is the function of the choroid layer? What is the function of the external ocular muscles?

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Exercise 5: Autonomic Reflexes
Autonomic reflexes are regulated by the autonomic division of the nervous system. They include the pupillary (light), and ciliospinal reflexes among others. In this exercise, the effects of these reflexes will be tested.

PROCEDURE:
1. The pupillary reflex involves the retina of your eye (receptor), the optic nerve (cranial nerve II as the sensory afferent neuron), the oculomotor nerve (cranial nerve III as the motor efferent neuron), and the smooth muscle of the iris as the effector. Refer to Figure 4 for the locations of the cranial and oculomotor nerves. 2. A dark room or a room with relatively dim light is necessary to perform this exercise. 3. Retrieve the flashlight and metric ruler from the dissecting kit in the LabPaq. 4. Use the metric ruler to measure the diameter of the subject’s pupils in each eye as accurately as you can. Record this value in the Lab Report Assistant.
Figure 6 – Use a metric ruler to measure the diameter of the subject’s pupils as accurately as possible.

5. Record the diameter of each pupil in the Lab Report Assistant. 6. Stand to the left of the subject and have the subject shield his right eye with his right hand. 7. Shine the flashlight into the subject’s left eye and carefully observe what happens. Measure the diameter of the pupil as accurately as possible with the light shining in it. 8. Record your observations in the Lab Report Assistant. 9. Observe the right pupil as you shine light into the left eye. Do you see the same reaction in the right pupil as you did in the left pupil? Record your observations in the Lab Report Assistant.
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10. To initiate the ciliospinal reflex, move to a brightly lit room (or light the room in which the pupillary reflex test was performed). 11. Face the subject eye-to-eye and gently stroke the skin or the hair on the left side of his or her neck next to the hairline. Watch what happens to the pupils. 12. If you see no reaction, repeat the test with a gentle pinch in the same area. 13. Record your observations in the Lab Report Assistant.

Questions: A. B. What is the function of the pupillary reflex? Is the sympathetic or parasympathetic division of the autonomic nervous system at work during these tests? Explain your reasoning.

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Exercise 6: Blindspots and Afterimages
In this exercise, you will test two interesting phenomena associated with sight. First we will look for the blind spot, which is the area of the retina that lacks photoreceptors. When light hits this area at the right angle an image will disappear from sight. The second phenomenon is the afterimage. Your photoreceptors use chemicals called photo pigments to stimulate membranes and transmit signals to the brain (refer to your textbook for an explanation of this process). The recycling of these chemicals takes time between images and often results in a “negative” afterimage being “seen” when your eyes are closed.

PROCEDURE:
Note: A partner is required for this exercise. 1. Retreive the 3x5-inch note card. 2. Using the metric ruler from the dissecting kit in the LabPaq, measure an 8x5-cm rectangle on the card and cut it out with scissors. Keep the 8x5-cm rectangular card and discard the rest of the card. 3. Using the ruler, measure about 1/2 cm toward the center of the cut-out card from the center left edge. Mark this spot with an X using the marking pencil. 4. Using the ruler, measure about 1/2 cm toward the center of the cut-out card from the center right edge. Mark this spot with a dot using the marking pencil.
Figure 7 – Mark the note card with an x and a dot.

5. Hold the card out about 18 inches from your eyes. Make sure the X is on the left and the dot is on the right. 6. Close the left eye and focus on the X with the right eye. 7. Move the card slowly toward your face and keep the right eye focused on the X.
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8. As you slowly move the card toward you, the black dot will disappear. 9. Stop moving the card when the dot disappears. 10. Ask the partner to measure the distance from your eyes to the card. Record this distance in the Lab Report. 11. Move the card closer and the dot will reappear as it moves out of the blind spot. 12. Repeat the exercise for the left eye. This time keep the right eye closed and focus the left eye on the dot. 13. Move the card closer toward your face until the X disappears. Ask the partner to measure the distance from your eyes to card and record the distance in the Lab Report. 14. Stare out of a bright window or at a bright lamp for one minute. 15. Close your eyes for one minute and pay attention to what you “see” while your eyes are closed. 16. Record the sequence of what you saw with your eyes closed in the Lab Report Assistant. These are called afterimages. Questions: A. B. Why do we have a blind spot? What causes an afterimage?

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Exercise 7: Taste and Smell
Taste and smell are two senses that are closely integrated. These two senses share afferent pathways to the brain, and therefore are influenced by the same stimuli. Both taste buds and olfactory bulbs are in a group of receptors known as chemoreceptors (they respond to chemical stimuli). When sensing smell, the aromatic gases released by substances trigger a response. In the nose, moist olfactory epithelium takes chemicals from the air and traps them on its surface. The epithelium contains olfactory receptor cells that can recognize these chemicals and send signals to the brain via an olfactory nerve. See Figure 8.
Figure 8 – Olfactory anatomy.

Item Description 1 Olfactory nerve bulb 2 Nerve fibers – send signal to olfactory nerve 3 Olfactory epithelium 3-A Olfactory nerve fiber 3-B Olfactory receptor cell 3-C Olfactory hairs 4 Olfactory cells 5 Inner chamber of the nose 6 Hard palate

Smell and memory are closely related since the olfactory bulb is part of the brain’s limbic system. The limbic system is the part of the brain that is involved with emotion and memory. That is why smell is one of our strongest senses in terms of establishing long-term memories. Most people associate special times, places and people in their lives with a particular scent. Baking bread, perfume, the smell of a house, or the smell of a car may all evoke memories many years after the memories were established.

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When sensing taste, the receptors in the mouth are mostly located in taste buds on the tongue. Some taste buds are located on the palate as well. One taste bud holds 50-150 cells that sense taste. See Figure 9.
Figure 9 – Taste bud.

Item 1 2 3 4

Description Oral cavity Taste pore Taste receptor cell Gustatory nerve

Until recently, it was thought that humans had four different types of taste receptors, segregated on different parts of the tongue. These receptors responded to four groups of stimuli: sweet, sour, bitter, and salty. For almost a century, scientists erroneously believed that each taste stimuli could be discerned only by taste buds located on specific areas of the tongue. Scientists also believed that each taste bud could detect only one type of taste stimuli. From these beliefs a tongue map was created, which indicated sweet taste was detected only by the tip of the tongue; salty tastes only by the front sides of the tongue; sour tastes only by the backsides of the tongue; and bitter tastes only by the back of the tongue. In 1974, American scientist Virginia Collings re-examined the differences in taste perception across the tongue. Collings determined that while individual taste buds do react more strongly to one particular taste, each taste bud could actually detect all four-taste stimuli. In other words, the tongue map was wrong in segregating tastes to specific areas of the tongue. Researchers now know taste buds can also be found on the soft palate and other parts of the mouth. Research suggests there may be a fifth receptor for a taste called umami and hints there may be a sixth, yet unnamed, receptor for fats. The taste sensation attributed to umami was identified by Japanese scientist Kikunae Ikeda in 1908, but it has only recently begun to gain acceptance in the West. The taste of umami is associated with glutamate, an amino acid found in meat, cheese, and other protein-heavy foods, as well as in monosodium glutamate (MSG).
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Umami taste buds can also sense some nucleotides. Scientists are still unsure whether umami, which roughly translates to “deliciousness,” but can mean "meaty" or "savory," is a universal taste, because only the Japanese and Chinese have a word for it.

PROCEDURE:
In this exercise, you will test the association between taste and smell. 1. A partner or family member is needed to perform this exercise. 2. Obtain four small cups or glasses and a spoon. Use the marking pencil to label the cups: salty, sweet, sour and bitter. 3. In the “salty” cup, make a salty solution by adding 1 teaspoon of salt to 4 oz (1/2 cup) of water. Stir until the salt is dissolved. Rinse off the spoon with tap water. 4. In the “sweet” cup, make a sugary solution by adding 1 teaspoon of sugar to 4 oz. (1/2 cup) of water. Stir until the sugar is dissolved. Rinse off the spoon with tap water. 5. In the “sour” cup, pour in 1/2 cup (4 oz) of lemon juice. 6. In the “bitter” cup, pour in a 1/2 cup of strong, black coffee. 7. Get four cotton swabs. Place one swab in each of the cups of solution. 8. Have the subject rinse his or her mouth out with water and dry the tongue with a paper towel. KEEP THE TONGUE OUT! 9. Take the swab from the salty solution and touch it to the center, back, tip and sides of the tongue. 10. Where can the subject taste the salt? Mark the tongue diagram in the lab report with O’s to indicate the presence of salt receptors. 11. Ask the subject rinse his or her mouth out again and repeat the procedure in step 9 for sweet, sour and bitter solutions. Important: BE SURE TO RINSE OUT THE MOUTH BETWEEN EACH TEST. 12. Repeat step 10. Use a “W” to indicate an area where many sweet receptors are located, a “U” to indicate an area where many sour receptors are located, and a “B” to indicate an area where many bitter receptors are located. 13. Get out the four, labeled empty pipettes from the LabPaq. 14. Place one pipette into each of the cups of solution.

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15. Ask the subject to rinse out his mouth with water. 16. Ask the subject to open his mouth and place four drops of salty solution on the center of his tongue. 17. Ask the subject to close his mouth and taste and swallow the solution. 18. Then ask the subject to pinch his nose shut and repeat the test with the salty solution. Ask him to close his mouth and taste and swallow with his nose pinched shut the whole time. Was the taste different with the nose shut? 19. Record the observations in the Lab Report Assistant. 20. Repeat Steps 14 to 17 for sweet, sour and bitter solutions. Important: ENSURE THAT THE SUBJECT RINSES OUT HIS MOUTH WITH WATER BETWEEN EACH TEST. Questions: A. B. C. Why are taste and smell receptors called chemoreceptors? Why is taste so closely associated with smell? Propose a reason why appetite may be lost when someone has a head cold.

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Exercise 8: Hearing
Sound waves are conducted into the inner ear to allow for the sense of hearing. Sound conducts better through liquids and solids than through the air. To take advantage of this property of sound, our inner ears use bones and a series of liquid-filled tubes to conduct sound. Receptors for hearing categorized as mechanoreceptors (they respond to physical stimuli such as vibration and pressure). The sound enters the ear and vibrates the tympanic membrane (ear drum), which then stimulates three small bones (the malleus, incus and stapes) to vibrate and send sound waves into the liquid-filled tubes, which end at the hairlike receptors. The hair-like receptors then stimulate cranial nerve VIII (vestibulocochlear nerve) to send the stimuli up the afferent pathway to the brain. Observe Figures 11 and 12 or refer to the Anatomy and Physiology textbook for other diagrams of these structures.
Figure 11 – Anatomy of the ear.

Item 1 2 3 4 5

Description Outer ear Middle ear Inner ear Bones of middle ear Semicircular canals

Item 6 7 8 9 10

Description Auditory nerve cochlea Oval window (where stirrup attaches) Eardrum Auditory canal

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Figure 12 – Closer look at the anatomy of the ear.

Item 1 2 3 4 5 6

Description Hammer Anvil Stirrup Cochlea, partially uncoiled Auditory cortex Auditory nerve

Item 7 8 9 10 11 12

Description Nerve fibers to auditory nerve Basilar membrane Motion of fluid in cochlea Oval window Eardrum (Tympanic membrane) Sound entering the ear canal

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PROCEDURE:
In this activity, you will observe the sense of hearing and perform the Weber test. 1. An assistant is necessary for this exercise. 2. Retrieve two cotton balls. 3. Obtain a watch, wall clock, or kitchen timer that ticks. 4. Ask the subject to pack one ear with a cotton ball and sit quietly in a chair. 5. Hold the watch or timer close to the subject’s unpacked ear. 6. Slowly move the watch or timer away from the ear until the subject says that he can no longer hear the ticking. 7. Measure the distance from the ear to where the sound was no longer heard by using a meter stick or measuring tape. Record this distance in the Lab Report Assistant. 8. Remove the cotton ball from the subject’s ear. 9. Ask the subject sit with his eyes closed. 10. Hold the watch or timer about 20 cm from his ear and move it to various locations and ask the subject point to where the sound is coming from in each instance (front, back, sides and above his head). 11. Can sound be localized equally as well from all points? Record the observations. 12. Obtain the tuning fork from the LabPaq. 13. To perform the Weber test, strike the tuning fork and place the handle medially on the top center of the subject’s head.
Figure 13 – Place the handle of the tuning fork medially on the top center of the subject’s head.

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14. Is the tone equally loud in both ears or is it louder in one ear? If the sound is heard equally loud in both ears, then there probably has been no hearing loss in either ear. Record observations in the Lab Report Assistant. 15. Strike the tuning fork and place the handle on your subject’s mastoid process (behind the ear). 16. When the subject indicates the sound is no longer audible, hold the prongs of the fork close to the ear canal and ask if he hears the fork again. If so, this is a positive test for air conduction and there is no hearing loss. Record the observations in the Lab Report. 17. Repeat the test, but this time do the air conduction at the ear canal first, and then move to the mastoid process. Record the observations in the lab report. 18. Repeat these tests with the other ear. Questions: A. B. How is sound conducted in the ear? Why are the cells responsible for hearing called mechanoreceptors?

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Exercise 9: Balance
Balance is a complex process. It involves receptors in the ear, the skin, the joints, and the muscles. The eyes judge distance and movement and these two senses are processed in two separate places in the brain: the cerebellum and brain stem. The body works together to use its senses to understand its environment. The Maculae in the vestibule of the inner ear contain hair cells, which are responsible for static equilibrium (balance without movement) and dynamic equilibrium (balance while moving). Equilibrium is maintained in the vestibular and semicircular canal portions of the bony labyrinth. Rotational acceleration and dynamic equilibrium is detected in the semicircular canals. The three semicircular canals − anterior, posterior and horizontal − are arranged at right angles to each other to represent all three axes in space. See Figure 14. The endolymph, a fluid in these canals moves in response to head movement and excite the hair cells lining the canals. Linear acceleration and static equilibrium are detected by the utricle and saccule. Inside the utricle and saccule is a sensory organ called the maculae which contain hair cells that sense orientation of the head in terms of gravitational direction and changes in direction or speed. The hair cells are embedded in a jelly-like membrane called the otolithic membrane. This membrane has small grains of calcium carbonate crystals called otoliths (literally this means “ear rocks”). When your head moves, the otoliths also move in response to the gravitational pull. The otoliths cause movement of the hair cells, which stimulate the vestibular nerve and send impulses to the brain.
Figure 14 − Inner Ear Anatomy.

Item 1 2 3 4 5 6 7

Desc iption Vestibular nerves Saccule Utricle Anterior semi-circular canal Posterior semi-circular canal Lateral semi-circular canal Cochlea

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PROCEDURE:
In this activity, the sense of balance will be tested. 1. An assistant is needed who will be the subject of this exercise. 2. Ask the subject to walk a straight line placing one foot directly in front of the other. Record what is seen in the Lab Report Assistant. 3. Answer Questions A and B in the lab manual. 4. Ask the subject to stand straight, feet together, eyes open and looking forward for one minute. 5. Observe the subject carefully from all sides and note any signs of swaying or movement. Record what is seen in the Lab Report Assistant. 6. Repeat the test with the subject’s eyes closed. Record observations in the Lab Report Assistant. 7. Ask the subject stand eyes-open for one minute. Observe the subject from the subject’s side. 8. Observe the subject carefully and note any front to back swaying or movements. Record your observations in the Lab Report Assistant. 9. Repeat the test, this time with the subject’s eyes closed. Record the observations in the Lab Report Assistant. 10. Stand in front of the subject and ask the subject stand up straight, eyes open. 11. Ask the subject lift one foot off the floor about 12 inches and hold it there for one minute. 12. Observe the subject carefully and note any movements he makes. observations in the Lab Report Assistant. 13. Ask the subject to rest for two minutes. 14. Repeat the test, this time with the subject’s eyes closed. Record observations in the Lab Report Assistant. Record your

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Questions: A. B. C. Where is balance processed in the brain? What can be concluded about the effect of vision on balance? What is the function of the otolithic membrane?

Conclusions: What do sensory and reflex tests tell about the functions of the nervous system as a whole?

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APPENDIX

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Final Cleanup Instructions
Congratulations on completing your science course’s lab assignments! We hope you had a great science learning experience and that what you’ve learned in this course will serve you well in the future. Studying science at a distance and performing laboratory experiments independently are certainly not easy tasks, so you should be very proud of your accomplishments. Since LabPaqs often contain potentially dangerous items, it is important that you perform a final cleanup to properly dispose of any leftover chemicals, specimens, and unused materials. Please take a few minutes to protect others from possible harm and yourself from future liability by complying with these final cleanup instructions. While you may wish to sell your used LabPaq, this is not advisable and would be unfair to a potential purchaser. It is unlikely that a new student trying to utilize a used LabPaq would have adequate quantities or sufficiently fresh chemicals and supplies to properly perform all the experiments and to have an effective learning experience. Further, it is doubtful that adequate safety information would be passed on to a new student in the same way it was presented to you. This is a significant concern and one of the reasons why a new user would not be covered by LabPaq’s insurance. Instead, you would be responsible for any problems experienced by a new user. Chemical Disposal  Due to the minute quantities, low concentrations, and diluted and/or neutralized chemicals used in LabPaqs, it is generally sufficient to blot up any remaining chemicals with paper towels and dispose of them in a trash bin or flush remaining chemicals down a drain with copious amounts of water. Empty dispensing pipets and bottles can be placed in a normal trash bin. These disposal methods are well within acceptable levels of the waste disposal guidelines defined for the vast majority of state and community solid and wastewater regulations. However, since regulations can vary in some communities, if you have any doubts or concerns, you should check with your area authorities to confirm compliance with local regulations and/or if assistance with disposal is desired. Specimen and Supply Disposal  To prepare any used dissection specimens for normal garbage disposal, wrap them in news or waste paper and seal them in a plastic bag before placing them in a securely covered trash container that will prevent children and animals from accessing the contents.

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Non chemical supplies can also be discarded with household garbage, but should first be wrapped in news or waste paper. Place such items in a securely covered trash container that will prevent children and animals from accessing the contents.

Lab Equipment  Many students choose to keep the durable science equipment included with their LabPaq as most of these items may have future utility or be used for future science exploration. However, take care to store any dangerous items, especially dissection knives and breakable glass, out of the reach of children. Please do not return items to LabPaq as we are unable to resell items or issue any refunds.

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Best wishes for a happy and successful future! The LabPaq Team

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