1.1 Explain The Principles Of Homeostasis Research

VTCT Sport & Active LeisureL3 Certificate in Sports Massage Therapy (QCF) |

Assignment 1 – Functional Anatomy & Physiology Unit UV30378 |

Lou Davidson – March 2012 |

1a – Explain the structures of a human cellMost human cells contain small structures known as organelles (“little organs”), each of which performs a highly specialised task, such as manufacturing protein. Organelles are usually surrounded by a membrane, and they float in a jelly-like substance called cytoplasm. Ninety percent of cytoplasm is water; it also contains enzymes, amino acids, and other molecules needed for cell functions. The structure
of a human cell can be broken down more microscopically as follows: * Nucleus – The cells control centre mainly contains chromatin, a granular material composed of DNA, the cells genetic material, and proteins. The inner nucleolus is made up of RNA and proteins. The nucleus is surrounded by the nuclear envelope, a two-layered membrane with pores. * Centrioles - These two structures made of hollow tubules play a key role in cell division. * Mitochondrion – This structure produces a substance called adenosine triphosphate (ATP), which is the carrier of energy in all cells. * Endoplasmic Reticulum – This organelle helps to transport materials through the cell. Rough reticulum is the site of attachment for ribosomes; smooth reticulum is the site of fat production. * Ribosomes – These small, granular structures play a key role in the assembly of proteins. * Golgi Complex – A stack of flattened sacs receives and processes protein that has been dispatched by the endoplasmic reticulum. The proteins are modified and released at the cell membrane. * Microvilli – Some cells, such as those lining the small intestine, have projections that increase their surface area to facilitate absorption. * Lysosome – The powerful enzymes of this organelle degrade dangerous materials taken into the cell, such as bacteria, and also dispose of other unwanted substances and any worn-out organelles. * Cell Membrane – The membrane encloses the contents of the cell and regulates the flow of substances into and out of the cell. * Vacuole – This sac transports and sores ingested materials, waste products, and water. * Visicles – These sacs contain various substances, such as enzymes, produced by the cell; they secrete them at the cell membrane. * Nucleolus – A small structure inside the nucleus that plays an important role in ribosome production. * Peroxisome – Enzymes that are made in these sacs oxidize some cell substances * Cytoskelton – The internal framework of the cell is made of two main types of structure. Prominent in all cells are filaments, which are thought to provide support for the cell. Hollow microtubules are thought to aid movement of substances through the cells watery cytoplasm. 1b – Describe the processes of osmosis and diffusionOsmosis may occur when there is a partially permeable membrane, such as a cell membrane. When a cell is submerged in water, the water molecules pass through the cell membrane from an area of low solute concentration (outside the cell) to one of high solute concentration (inside the cell); this is called osmosis. The cell membrane is selectively permeable, so only necessary materials are let into the cell and wastes are left out.Diffusion is a main form of transport for necessary materials such as amino acids within cells. Metabolism and respiration rely in part upon diffusion in addition to bulk or active processes. For example, in the alveoli of the lungs, due to differences in partial pressures across the alveolar-capillary membrane, oxygen diffuses into the blood and carbon dioxide diffuses out. Lungs contain a large surface area to facilitate this gas exchange process.1c – Explain Basal Metabolic Rate Basal metabolic rate and the closely related resting metabolic rate, is the amount of energy expended daily whilst at rest. Your BMR is the estimated minimum level of energy required to sustain the body’s vital functions. The Harris-Benedict formula is used to calculate BMR. English BMR Formula | Women: BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years )
Men: BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in year ) |
1d – Explain the principles of homeostasis Homeostasis is the way the body maintains a stable internal environment.
It is important for the body to have a stable environment for cells to function correctly. There are several things that need to be regulated: 1. The body's temperature. If temperature were allowed to rise out of control, protein and therefore enzyme, structure would be affected, perhaps with disastrous results. 2. The amount of water within the body. The levels of water can affect metabolism and osmosis. Again this can have serious consequences. 3. The amount of glucose in the body. This level can also affect osmosis and obviously the rate of respiration as well. 4. The amount of nitrogenous waste in the body. Nitrogenous waste can become toxic in the body. It is important that this level does not get too high.Negative feedbackTo regulate these things the body needs firstly to detect the level and then to respond in an appropriate way. For temperature, water and glucose there is a level called the 'norm' (e.g., normal body temperature is 36.9°C). If the level gets too high this triggers the body to lower it. If the level gets too low this triggers the body to raise it. This is the principle of negative feedback. (Positive feedback is when a high level of something triggers the body to increase it even further). 1e – Describe the structures and functions of the different types of human tissues Tissues of the human body can be broken down into categories
: Epithelial Tissues – Epithelial tissue, or epithelium, is found in skin and, in diverse forms, has special functions in other body areas. The main types are: simple epithelium, a single layer squamous (flat), cuboidal (cube-like), or columnar (tall) cells; stratified epithelium, with two or more layers; pseudostratified epithelium, which looks stratified, but has only one layer of columnar cells that have surface hairs (cilia) or secrete mucus; and transitional epithelium, which is multi-layered and pliable. The primary function of epithelial tissue is protection. Glandular Tissues - Glandular tissue is tissue that is designed to secrete something. It is one of the major forms of epithelial tissue, which is the tissue that lines and covers most of the body, from the skin to the inside of the stomach. There are several different kinds of glandular tissue, differentiated by how they function.One type of glandular tissue is endocrine tissue, the material found in the endocrine glands. Endocrine glands produce hormones, which are chemical messengers that travel throughout the body to mediate and control various functions. An example of an endocrine gland is the thyroid, a gland found in the neck that produces thyroid hormone. This type of glandular tissue is capable of producing secretions that can enter the bloodstream, allowing them to be distributed to many different areas inside the body.Exocrine glandular tissue makes secretions that are designed to travel through the tissue to the surface along tube-like structures, having an impact in the immediate surrounding area. These glands do not make chemical messengers; they produce secretions like breast milk, sweat, and mucus. For instance, the salivary glands are made up of exocrine glandular tissue that produces saliva, an oral fluid designed to lubricate the mouth and begin the process of breaking down food. Exocrine tissue has a localized effect in contrast with the whole-body effects produced by endocrine tissue. Connective Tissues - Connective tissue is a fibrous and most diverse tissue. Connective Tissue (CT) is found throughout the body. In fact the whole framework of the skeleton and the different specialized connective tissues from the crown of the head to the toes determine the form of the body and act as an entity. CT has 3 main components: cells, fibers, and extracellular matrix, all embedded in the body fluids. Fibroblasts are the cells responsible for the production of connective tissue. The interaction of the fibers, the extracellular matrix and the water, together, form the pliable connective tissue as a whole. Connective tissue makes up a variety of physical structures including tendons and the connective framework of fibers in muscles, capsules and ligaments around joints, cartilage, bone, adipose tissue, blood and lymphatic tissue. CT is classified into three subtypes; Embryonic CT, Proper CT, and Special CT. The Proper CT subtype includes dense regular CT, dense irregular CT, and loose CT. The Special CT subtype includes cartilage, bone, adipose tissue, blood, hematopoietic tissue (tissue that makes blood cells) and lymphatic tissue as well as the most abundant protein in mammals, Type-I collagen, making up about 25% of the total protein content. The function of connective tissue is the storage of energy, protection of organs, and provision of structural framework for the body and the connection of body tissues. Bone Tissues - Bone tissue occurs in the different bones of the skeleton. Bone is a hard and rigid tissue. Like cartilage, bone consists of living cells with large amounts of ground substance or matrix. It is impregnated with organic salts such as calcium carbonate (7%) and calcium phosphate (85%). Small amounts of sodium and magnesium is also present. In addition to this, the matrix contains numerous collagenous fibres and a large amount of water. Collagen fibres together with the bone cells constitute the organic (living) matter in bone tissue. There are different groups of bone in the skeleton, inter alia long bones such as the humerus and femur. The skeleton is built of bone tissue. Bone provides the internal support of the body and provides sites of attachment of tendons and muscles, essential for locomotion. Bone provides protection for the vital organs of the body: the skull protects the brain; the ribs protect the heart and lungs. The hematopoietic bone marrow is protected by the surrounding bony tissue. The main store of calcium and phosphate is in bone. Bone has several metabolic functions especially in calcium homeostasis.Lymphoid Tissues - The part of the body's immune system that is important for the function of the immune response and helps protect it from infection and foreign bodies. Lymphoid tissue is present throughout the body and includes the lymph nodes, spleen, tonsils, adenoids, and other structures. Nervous Tissues - Nervous tissue is one of four major classes of vertebrate tissue. It is the specialized tissue that makes up the central nervous system and the peripheral nervous system, consisting of neurons with their processes, other specialized or supporting cells, and extracellular material. Nervous tissue is the main component of the nervous system - the brain, spinal cord, and nerves-which regulates and controls body functions. It is composed of neurons, which transmit impulses, and the neuroglia cells, which assist propagation of the nerve impulse as well as provide nutrients to the neuron. Nervous tissue is made of nerve cells that come in many varieties, all of which are distinctly characteristic by the axon or long stem like part of the cell that sends action potential signals to the next cell. Functions of the nervous system are sensory input, integration, controls of muscles and glands, homeostasis, and mental activity. Muscle Tissue - Muscle is a very specialized tissue that has both the ability to contract and the ability to conduct electrical impulses. Muscles are classified both functionally as either voluntary or involuntary and structurally as either striated or smooth. From this, there emerges three types of muscles: smooth involuntary (smooth) muscle, striated voluntary (skeletal) muscle and striated involuntary (cardiac) muscle. The names in the brackets are the common names given to the particular classification of muscle.Functions of Smooth Muscle Tissue - Smooth muscle controls slow, involuntary movements such as the contraction of the smooth muscle tissue in the walls of the stomach and intestines. The muscle of the arteries contracts and relaxes to regulate the blood pressure and the flow of blood. Functions of Skeletal Muscle Tissue - Skeletal muscles function in pairs to bring about the co-ordinated movements of the limbs, trunk, jaws, eyeballs, etc. Skeletal muscles are directly involved in the breathing process. Functions of Cardiac (Heart) Muscle Tissue - Cardiac muscle tissue plays the most important role in the contraction of the atria and ventricles of the heart. It causes the rhythmical beating of the heart, circulating the blood and its contents throughout the body as a consequence. 2a – Describe the structure of skin & 2b – Explain the functions of skin The skin has three layers—the epidermis, dermis, and fat layer (also called the subcutaneous layer). Each layer performs specific tasks.Epidermis: The epidermis is the relatively thin, tough, outer layer of the skin. Most of the cells in the epidermis are keratinocytes. They originate from cells in the deepest layer of the epidermis called the basal layer. New keratinocytes slowly migrate up toward the surface of the epidermis. Once the keratinocytes reach the skin surface, they are gradually shed and are replaced by younger cells pushed up from below.The outermost portion of the epidermis, known as the stratum corneum, is relatively waterproof and, when undamaged, prevents most bacteria, viruses, and other foreign substances from entering the body. The epidermis (along with other layers of the skin) also protects the internal organs, muscles, nerves, and blood vessels against trauma. In certain areas of the body that require greater protection (such as the palms of the hands and the soles of the feet), the outer keratin layer of the epidermis (stratum corneum) is much thicker.Scattered throughout the basal layer of the epidermis are cells called melanocytes, which produce the pigment melanin, one of the main contributors to skin colour. Melanin's primary function, however, is to filter out ultraviolet radiation from sunlight, which can damage DNA, resulting in numerous harmful effects, including skin cancer.The epidermis also contains Langerhans' cells, which are part of the skin's immune system. Although these cells help detect foreign substances and defend the body against infection, they also play a role in the development of skin allergies.Dermis: The dermis, the skin's next layer, is a thick layer of fibrous and elastic tissue (made mostly of collagen, elastin, and fibrillin) that gives the skin its flexibility and strength. The dermis contains nerve endings, sweat glands and oil (sebaceous) glands, hair follicles, and blood vessels.The nerve endings sense pain, touch, pressure, and temperature. Some areas of the skin contain more nerve endings than others. For example, the fingertips and toes contain many nerves and are extremely sensitive to touch.The sweat glands produce sweat in response to heat and stress. Sweat is composed of water, salt, and other chemicals. As sweat evaporates off the skin, it helps cool the body. Specialized sweat glands in the armpits and the genital region (apocrine sweat glands) secrete a thick, oily sweat that produces a characteristic body odour when the sweat is digested by the skin bacteria in those areas.The sebaceous glands secrete sebum into hair follicles. Sebum is oil, which keeps the skin moist and soft and acts as a barrier against foreign substances.The hair follicles produce the various types of hair found throughout the body. Hair not only contributes to a person's appearance but has a number of important physical roles, including regulating body temperature, providing protection from injury, and enhancing sensation. A portion of the follicle also contains stem cells capable of re-growing damaged epidermis.The blood vessels of the dermis provide nutrients to the skin and help regulate body temperature. Heat makes the blood vessels enlarge (dilate), allowing large amounts of blood to circulate near the skin surface, where the heat can be released. Cold makes the blood vessels narrow (constrict), retaining the body's heat.Over different parts of the body, the number of nerve endings, sweat glands and sebaceous glands, hair follicles, and blood vessels varies. The top of the head, for example, has many hair follicles, whereas the soles of the feet have none.Fat Layer: Below the dermis lies a layer of fat that helps insulate the body from heat and cold, provides protective padding, and serves as an energy storage area. The fat is contained in living cells, called fat cells, held together by fibrous tissue. The fat layer varies in thickness, from a fraction of an inch on the eyelids to several inches on the abdomen and buttocks in some people.2c – Describe common pathologies that affect the skin There are different pathologies that can affect skin, which include: Bacterial skin infections include: * Impetigo is a highly contagious bacterial skin infection most common among young children. It is primarily caused by staph and sometimes by strep bacteria. It causes blistering of the skin. * Cellulitis is a diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters, burns, insect bites, surgical wounds. Skin on the face or lower legs is most commonly affected by this infection, though cellulitis can occur on any part of the body.Viral skin infections include: * Herpes – There are two types of herpes (HSV-1 & HSV-2). Type 1 is commonly known as cold-sores and type 2 is commonly known as genital herpes. Herpes is highly contagious and spread via saliva and genital secretions. It presents as inflamed lesions on the skin. * Shingles - This is a painful rash that is caused by a reactivation of the same virus that causes chicken pox. Not only is shingles a painful condition, but several complications can occur. Shingles, also called zoster or herpes zoster, is a skin rash caused by a viral infection of the nerves just below the skin. Shingles usually appears as a stripe of irritated skin and blisters on one side of the chest or back, but it can occur anywhere on the body, including on the face and near the eyes. * Warts & Verrucas - Warts are small, rough lumps on the skin that are benign (non-cancerous). They often appear on the hands and feet. Warts can look different depending on where they appear on the body and how thick the skin is. A wart on the sole of the foot is called a verruca. The clinical name for a verruca is a plantar wart. Warts are caused by infection with a virus known as the human papilloma virus (HPV). HPV causes keratin, a hard protein in the top layer of the skin (the epidermis) to grow too much. This produces the rough, hard texture of a wart.Fungal skin infections include: * Athletes Foot – Athlete’s foot is a common condition caused by a fungal infection. An itchy red rash develops in the spaces between your toes. As well as being itchy, the skin in the affected area may be scaly, flaky and dry. The medical name for athlete’s foot is tinea pedis.Skin allergies include: * Eczema & Dermatitis - Contact dermatitis is inflammation of the skin that occurs when you come into contact with a particular substance. It can cause red, itchy and scaly skin, and sometimes burning and stinging. Contact dermatitis is a type of eczema. This is the name for a group of skin conditions that cause dry, irritated skin. There are several other types of eczema, including: * atopic eczema (also called atopic dermatitis), which often runs in families and is linked to other conditions, such as asthma and hay fever * discoid eczema, which usually affects adults and causes circular or oval patches of eczema * varicose eczema, which occurs on the legs, usually around varicose veins (swollen and enlarged veins) There are two types of contact dermatitis: * allergic contact dermatitis - this is caused by an allergen (a substance that causes an immune response in the skin) * irritant contact dermatitis - this is caused by an irritant (a substance that damages the skin physically) * Psoriasis - Psoriasis is a skin condition that causes red, flaky, crusty patches of skin covered with silvery scales. The condition is not infectious and most people are affected only in small patches on their body. Psoriasis affects around 2% of people in the UK. It can start at any age, but most often develops between the ages of 11 and 45. The severity of psoriasis varies greatly from person to person. For some people, it is just a minor irritation, but for others it has a major impact on their quality of life. Psoriasis is a long-lasting (chronic) disease that can return at any time. There may be times when you have no symptoms or very mild symptoms, followed by times when the symptoms are severe.Other skin conditions include : * Non-melanoma skin cancer refers to a group of skin cancers that affect the upper layers of skin. The term 'non-melanoma' distinguishes these generally more common kinds of skin cancer from the less common, aggressive skin cancer known as melanoma. * Corns - Corns are small circles of thick skin that usually develop on the tops and sides of toes or on the sole of the foot. However, they can occur anywhere. Women often get them if they've been wearing badly fitting shoes or spent a lot of time standing during the day. Corns often occur on bony feet as there's a lack of natural cushioning. They can also develop as a symptom of another foot problem, such as a bunion (a bony swelling at the base of the big toe) or hammer toe (where the toe is bent at the middle joint).Understand the structure and functions of the musculoskeletal system 3a – Anatomical Planes Planes refer to the two-dimensional sections through the body, to give a view of the body or body part, as if it has been cut through and imaginary line.

- The Sagittal (vertical) Plane cuts through the body from anterior to posterior, dividing the body into the right and left halves.
- The Frontal (coronal) Plane passes vertically through the body, dividing the body in to anterior (front)and posterior (back) sections, and lies at right angles to the sagittal plane
- The Transverse (Axial) Plane cuts the body horizontally, dividing the body into upper (superior) and lower (inferior) sections, and lies at right angles to the two other planes.3a – Directional Terms To describe the relative position of body parts and their movements, it is essential to have a universally accepted initial reference position. The standard body position known as the anatomical position serves as this reference. The anatomical position is simply the upright standing position with arms hanging by the sides, palms facing forward.

Anterior(ventral) - Refers to the front of the body (in front of; toward the front)
Posterior(dorsal) - Refers to the back of the body (behind; toward the backside of the body)
Superior - Refers to the upper part of the body (above; toward the head)
Inferior - Refers to the lower part of the body (below; away from the head)
Medial - Toward or at the midline of the body on the inner side of a limb
Lateral – Away from the midline of the body; on the outer side of the body or limbProximal – Closer to the centre of the body (the navel), or to the point of attachment of a limb to the body. (e.g. The elbow is proximal to the hand) Distal – Farther from the centre of the body, or from the point of attachment of a limb to the body. (e.g. The hand is distal to the elbow) Superficial – Toward or at the body surface Deep – Farther away from the body surface; more internal
3b – Structure and Functions of Different Types of Bone Composition of BoneBones are rigid organs that constitute part of the endoskeleton of vertebrates.
They support and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue. Bones come in a variety of shapes and have a complex internal and external structure, are lightweight yet strong and hard, and serve multiple functions. One of the types of tissue that makes up bone is the mineralized osseous tissue, also called bone tissue that gives it rigidity and a coral-like three-dimensional internal structure. Other types of tissue found in bones include marrow, endosteum, periosteum, nerves, blood vessels and cartilage.Compact (cortical) boneThe hard outer layer of bones is composed of compact bone tissue, so-called due to its minimal gaps and spaces. Its porosity is 5–30%.[6] This tissue gives bones their smooth, white, and solid appearance, and accounts for 80% of the total bone mass of an adult skeleton. Compact bone may also be referred to as dense bone.Trabecular (cancellous) boneFilling the interior of the bone is the trabecular bone tissue (an open cell porous network also called cancellous or spongy bone), which is composed of a network of rod- and plate-like elements that make the overall organ lighter and allow room for blood vessels and marrow. Trabecular bone accounts for the remaining 20% of total bone mass but has nearly ten
times the surface area of compact bone. Its porosity is 30–90%.[6] If, for any reason, there is an alteration in the strain the cancellous is subjected to, there is a rearrangement of the trabeculae. The microscopic difference between compact and cancellous bone is that compact bone consists of haversian sites and osteons, while cancellous bones do not. Also, bone surrounds blood in the compact bone, while blood surrounds bone in the cancellous bone.Types of Bone There are five different types of bone which include; Long - Long bones are some of the longest bones in the body, such as the Femur, Humerus and Tibia but are also some of the smallest including the Metacarpals, Metatarsals and Phalanges. The classification of a long bone includes having a body which is longer than it is wide, with growth plates (epiphysis) at either end, having a hard outer surface of compact bone and a spongy inner known as cancellous bone containing bone marrow. Both ends of the bone are covered in hyaline cartilage to help protect the bone and aid shock absorption.Short- Short bones are defined as being approximately as wide as they are long and have a primary function of providing support and stability with little movement. Examples of short bones are the Carpals and Tarsals - the wrist and foot bones. They consist of only a thin layer of compact, hard bone with cancellous bone on the inside along with relatively large amounts of bone marrow. Flat - Flat bones are as they sound, strong, flat plates of bone with the main function of providing protection to the body’s vital organs and being a base for muscular attachment. The classic example of a flat bone is the Scapula (shoulder blade). The Sternum (breast bone), Cranium (skull), os coxae (hip bone) Pelvis and Ribs are also classified as flat bones. Anterior and posterior surfaces are formed of compact bone to provide strength for protection with the centre consisting of cancellous (spongy) bone and varying amounts of bone marrow. In adults, the highest number of red blood cells are formed in flat bones. Irregular - These are bones in the body which do not fall into any other category, due to their non-uniform shape. Good examples of these are the Vertebrae, Sacrum and Mandible (lower jaw). They primarily consist of cancellous bone, with a thin outer layer of compact bone.Sesamoid - Sesamoid bones are usually short or irregular bones, imbedded in a tendon. The most obvious example of this is the Patella (knee cap) which sits within the Patella or Quadriceps tendon. Other sesamoid bones are the Pisiform (smallest of the Carpals) and the two small bones at the base of the 1st Metatarsal. Sesamoid bones are usually present in a tendon where it passes over a joint which serves to protect the tendon.3c - Explain the structure and function of muscle tissue

We know that living organisms can move on their own or can perform other types of movement. Muscle tissue has an ability to relax and contract and so bring about movement and mechanical work in various parts of the body. There are other movements in the body too which are necessary for the survival of the organism such as the heart beat and the movements of the alimentary canal.

Muscles can be divided into three main groups according to their structure, e.g.:

Smooth muscle tissue.
Skeletal muscle tissue.
Cardiac (heart) muscle tissue.

Smooth Muscle Tissue
Smooth muscle tissue is made up of thin-elongated muscle cells, fibres. These fibres are pointed at their ends and each has a single, large, oval nucleus. Each cell is filled with a specialised cytoplasm, the sarcoplasm and is surrounded by a thin cell membrane, the sarcolemma. Each cell has many myofibrils which lie parallel to one another in the direction of the long axis of the cell. They are not arranged in a definite striped (striated) pattern, as in skeletal muscles - hence the name smooth muscle. Smooth muscle fibres interlace to form sheets or layers of muscle tissue rather than bundles. Smooth muscle is involuntary tissue, i.e. it is not controlled by the brain. Smooth muscle forms the muscle layers in the walls of hollow organs such as the digestive tract (lower part of the oesophagus, stomach and intestines), the walls of the bladder, the uterus, various ducts of glands and the walls of blood vessels.
Functions of Smooth Muscle Tissue - Smooth muscle controls slow, involuntary movements such as the contraction of the smooth muscle tissue in the walls of the stomach and intestines. The muscle of the arteries contracts and relaxes to regulate the blood pressure and the flow of blood.

Skeletal Muscle Tissue
Skeletal muscle is the most abundant tissue in the vertebrate body. These muscles are attached to and bring about the movement of the various bones of the skeleton, hence the name skeletal muscles. The whole muscle, such as the biceps, is enclosed in a sheath of connective tissue, the epimysium. This sheath folds inwards into the substance of the muscle to surround a large number of smaller bundles, the fasciculi. These fasciculi consist of still smaller bundles of elongated, cylindrical muscle cells, the fibres. Each fibre is a syncytium, i.e. a cell that have many nuclei. The nuclei are oval in shaped and are found at the periphery of the cell, just beneath the thin, elastic membrane (sarcolemma). The sarcoplasm also has many alternating light and dark bands, giving the fibre a striped or striated appearance (hence the name striated muscle). With the aid of an electron microscope it can be seen that each muscle fibre is made up of many smaller units, the myofibrils. Each myofibril consists of small protein filaments, known as actin and myosin filaments. The myosin filaments are slightly thicker and make up the dark band (or A-band). The actin filaments make up the light bands (I-bands) which are situated on either side of the dark band. The actin filaments are attached to the Z-line. This arrangement of actin and myosin filaments is known as a sacromere. Skeletal muscle is mainly voluntary as a conscious decision has to be made to activate a muscle and produce movement; however there are some involuntary fibres that assist with balance and posture. Functions of Skeletal Muscle Tissue - Skeletal muscles function in pairs to bring about the co-ordinated movements of the limbs, trunk, jaws, eyeballs, etc. Skeletal muscles are directly involved in the breathing process.
Cardiac (Heart) Muscle Tissue
This is a unique tissue found only in the walls of the heart. Cardiac (Heart) Muscle Tissue shows some of the characteristics of smooth muscle and some of skeletal muscle tissue. Its fibres, like those of skeletal muscle, have cross-striations and contain numerous nuclei. However, like smooth muscle tissue, it is involuntary. Cardiac muscle differ from striated muscle in the following aspects: they are shorter, the striations are not so obvious, the sarcolemma is thinner and not clearly discernible, there is only one nucleus present in the centre of each cardiac fibre and adjacent fibres branch but are linked to each other by so-called muscle bridges. The spaces between different fibres are filled with areolar connective tissue which contains blood capillaries to supply the tissue with the oxygen and nutrients.
Functions of Cardiac (Heart) Muscle Tissue - Cardiac muscle tissue plays the most important role in the contraction of the atria and ventricles of the heart. It causes the rhythmical beating of the heart, circulating the blood and its contents throughout the body as a consequence.
3d - Describe the sliding filament theoryThe sliding filament theory is the method by which muscles are thought to contract. At a very basic level each muscle fibre is made up of smaller fibres called myofibrils. These contain even smaller structures called actin and myosin filaments. These filaments slide in and out between each other to form a muscle contractions, hence called the sliding filament theory.Here is a quick reminder of all the structures involved:

Myofibril: A cylindrical organelle running the length of the muscle fibre, containing Actin and Myosin filaments.
Sarcomere: The functional unit of the Myofibril, divided into I, A and H bands.
Actin: A thin, contractile protein filament, containing 'active' or 'binding' sites.
Myosin: A thick, contractile protein filament, with protrusions known as Myosin Heads.
Tropomyosin: An actin-binding protein which regulates muscle contraction.
Troponin: A complex of three proteins, attached to Tropomyosin.
Here is what happens in detail. The process of a muscle contracting can be divided into 5 sections:

A nervous impulse arrives at the neuromuscular junction, which causes a release of a chemical called Acetylcholine. The presence of Acetylcholine causes the depolarisation of the motor end plate which travels throughout the muscle by the transverse tubules, causing Calcium (Ca+) to be released from the sarcoplasmic reticulum.

In the presence of high concentrations of Ca+, the Ca+ binds to Troponin, changing its shape and so moving Tropomyosin from the active site of the Actin. The Myosin filaments can now attach to the Actin, forming a cross-bridge.

The breakdown of ATP releases energy which enables the Myosin to pull the Actin filaments inwards and so shortening the muscle. This occurs along the entire length of every myofibril in the muscle cell.

The Myosin detaches from the Actin and the cross-bridge is broken when an ATP molecule binds to the Myosin head. When the ATP is then broken down the Myosin head can again attach to an Actin binding site further along the Actin filament and repeat the 'power stroke'. This repeated pulling of the Actin over the myosin is often known as the ratchet mechanism.

This process of muscular contraction can last for as long as there is adequate ATP and Ca+ stores. Once the impulse stops the Ca+ is pumped back to the Sarcoplasmic Reticulum and the Actin returns to its resting position causing the muscle to lengthen and relax.
It is important to realise that a single power stroke results in only a shortening of approximately 1% of the entire muscle. Therefore to achieve an overall shortening of up to 35% the whole process must be repeated many times. It is thought that whilst half of the cross-bridges are active in pulling the Actin over the Myosin, the other half are looking for their next binding site.

3 e - Explain the coordinated action of muscles and types of contraction

Muscles work together, or in opposition, to achieve a wide variety of movements. Therefore, whatever one muscle can do, there is another muscle that can undo it. In addition to movement, some muscles work as stabilisers for support, which in turn allow movement elsewhere. The four functional groups of muscles are: Prime Mover or Agonist – A prime mover (agonist) is a muscle that contracts to produce a specified movement. An example is the biceps brachii, which is the prime mover of elbow flexion. Other muscles may assist the prime mover in providing the same movement, albeit with less effect. Such muscles are called assistant or secondary movers. For example, the brachialis assists the biceps brachii in flexing the elbow, and is therefore the secondary mover.Antagonist – The muscles on the opposite side of the joint to the prime mover, and which must relax to allow the prime mover to contract, is called the antagonist. For example, when the biceps on the front of the arm contract to flex the elbow, the triceps on the back of the arm must relax to allow this movement to occur.Synergist - A synergist is a kind of muscle that performs, or helps perform, the same set of joint motion as the agonists. Synergist muscles act on movable joints. Synergists are sometimes referred to as "neutralizers" because they help cancel out, or neutralize, extra motion from the agonists to make sure that the force generated works within the desired plane of motion.Fixator – The functions of a fixator muscle is the stabilizing of the origin of the prime mover so that the prime mover can act more efficiently. Fixators steady the proximal end of a limb while movements occurs at the distal end. An example would be: the scapula is a freely movable bone that serves as the origin for several muscles that move the arm. When the arm contracts the scapula must be held steady.Types of muscle contraction Muscle Contractions can be divided into: * Isotonic (meaning same tension) - Isotonic contractions are those which cause the muscle to change length as it contracts and causes movement of a body part. There are two types of Isotonic contraction:Concentric Concentric contractions are those which cause the muscle to shorten as it contracts. An example is bending the elbow from straight to fully flexed, causing a concentric contraction of the Biceps Brachii muscle. Concentric contractions are the most common type of muscle contraction and occur frequently in daily and sporting activities. Eccentric Eccentric contractions are the opposite of concentric and occur when the muscle lengthens as it contracts. This is less common and usually involves the control or deceleration of a movement being initiated by the eccentric muscles agonist.For example, when kicking a football, the Quadriceps muscle contracts concentrically to straighten the knee and the Hamstrings contract eccentrically to decelerate the motion of the lower limb. This type on contraction puts a lot of strain through the muscle and is commonly involved in muscle injuries. * Isometric (meaning same distance or not moving) - Isometric contractions occur when there is no change in the length of the contracting muscle. This occurs when carrying an object in front of you as the weight of the object is pulling your arms down but your muscles are contracting to hold the object at the same level. Another example is when you grip something, such as a tennis racket. There is no movement in the joints of the hand, but the muscles are contracting to provide a force sufficient enough to keep a steady hold on the racket. The amount of force a muscle is able to produce during an isometric contraction depends on the length of the muscle at the point of contraction. Each muscle has an optimum length at which the maximum isometric force can be produced. * Isokinetic (meaning same speed) - Isokinetic contractions are similar to isotonic in that the muscle changes length during the contraction, where they differ is that Isokinetic contractions produce movements of a constant speed. To measure this special piece of equipment known as an Isokinetic Dynamometer is required. Examples of using isokinetic contractions in day-to-day and sporting activities are rare. The best is breast stroke in swimming, where the water provides a constant, even resistance to the movement of adduction.3 f - Outline the functions of the Skelton
The skeleton has many functions that include:
Support
The skeleton is the framework of the body it supports the softer tissues and provides points of attachment for most skeletal muscles.

Protection
The skeleton provides mechanical protection for many of the body's internal organs, reducing risk of injury to them.
For example, cranial bones protect the brain, vertebrae protect the spinal cord, and the ribcage protects the heart and lungs.

Assisting in Movement
Skeletal muscles are attached to bones, therefore when the associated muscles contract, they cause bones to move.

Storage of Minerals
Bone tissues store several minerals, including calcium (Ca) and phosphorus (P). When required, bone releases minerals into the blood - facilitating the balance of minerals in the body.

Production of Blood Cells
The red bone marrow inside some larger bones is where blood cells are produced.

Storage of Chemical Energy
With increasing age some bone marrow changes from 'red bone marrow' to 'yellow bone marrow'.
Yellow bone marrow consists mainly of adipose cells, and a few blood cells. It is an important chemical energy reserve.

3G - Describe the different types of joint that make up the human body

A joint is the point where two or more bones meet. There are three main types of joints; Fibrous (immoveable), Cartilagenous (partially moveable) and the Synovial (freely moveable) joint.

Fibrous joints
Fibrous (synarthrodial): This type of joint is held together by only a ligament. Examples are where the teeth are held to their bony sockets and at both the radioulnar and tibiofibular joints.

Cartilagenous
Cartilagenous (synchondroses and sympheses): These joints occur where the connection between the articulating bones is made up of cartilage for example between vertebrae in the spine.

A cartilagenous joint between two vertebrae
Synchondroses are temporary joints which are only present in children, up until the end of puberty. For example the epiphyseal plates in long bones. Symphesis joints are permanant cartilagenous joints, for example the pubic symphesis.
Synovial Joints
Synovial (diarthrosis): Synovial joints are by far the most common classification of joint within the human body. They are highly moveable and all have a synovial capsule (collagenous structure) surrounding the entire joint, a synovial membrane (the inner layer of the capsule) which secretes synovial fluid (a lubricating liquid) and cartilage known as hyaline cartilage which pads the ends of the articulating bones. There are 6 types of synovial joints which are classified by the shape of the joint and the movement available.

Types of Synovial Joint Name | Example | Description | Gliding joints (or planar joints) | the carpals of the wrist, acromioclavicular joint | These joints allow only gliding or sliding movements | Hinge joints | the elbow (between the humerus and the ulna) | These joints act as a door hinge does, allowing flexion and extension in just one plane | Pivot joints | Atlanto-axial joint, proximal radioulnar joint, and distal radioulnar joint | One bone rotates about another | Condyloid joints (or ellipsoidal joints) | the wrist joint (radiocarpal joint) temporomandibular joint | A condyloid joint is where two bones fit together with an odd shape (e.g. an ellipse), and one bone is concave, the other convex; some classifications make a distinction between condyloid and ellipsoid joints; these joints allow flexion, extension, abduction, and adduction movements (circumduction). | Saddle joints | Carpometacarpal or Trapeziometacarpal Joint of thumb (between the metacarpal and carpal - the trapezium), sternoclavicular joint | Saddle joints, which resemble a saddle, permit the same movements as the condyloid joints | Ball and socket joints"Universal Joint" | the shoulder (glenohumeral), and hip joints | These allow for all movements except gliding | Compound joints / Modified Hinge Joints | the knee joint | condylar joint (condyles of femur join with condyles of tibia) and saddle joint (lower end of femur joins with patella) |
3 h - Explain the structure of the major joints in the body
The major joints of the body include: The Shoulder - The shoulder is one of the most flexible of the body’s joints. The shoulder joint is what allows people to move their arms and, as a result, move their hands to where they need to be used. To be so flexible, the shoulder must have a wide range of movement. Unfortunately, this ability to move so freely means the shoulder joint is one of the less stable joints in the body.

The shoulder is a ball and socket joint. However, unlike other ball and socket joints in the body where the ball is nearly surrounded by the bone "cup" part of the joint, the ball end of the upper arm bone (humerus) instead rests in a shallow cup located on the end of the shoulder blade (scapula). A cuff of cartilage (labrum) forms an extended cup in which the ball end of the arm bone rests.

The entire shoulder joint is held in place by a complex arrangement of muscles, tendons and ligaments. Some of these muscles and tendons form the shoulder’s rotator cuff, a group of four tendons and four muscles that work together and form a "cuff" over the upper end of the arm. The four muscles are the subscapularis, the supraspinatus, the infraspinatus and the teres minor. The muscles start on the shoulder blade (scapula) and are connected to the upper part of the arm bone (humerus) by the tendons that are attached directly into the bone. The rotator cuff helps a person raise and rotate the arm and stabilize the shoulder within the joint.

In addition, the shoulder joint has a subacromial bursa, a fluid-filled cushioning sac between the deltoid muscle, the curved section of bone that forms the top of the shoulder (acromion) and the rotator cuff.The Shoulder Girdle – The pectoral girdle or shoulder girdle is the set of bones which connects the upper limb to the axial skeleton on each side. It consists of the clavicle and scapula. The pectoral girdle is a complex of five joints that can be divided into two groups. Three of these joints are true anatomical joints while two are physiological ("false") joints.[explain 1] Within each group, the joints are mechanically linked so that both groups simultaneously contribute to the different movements of the shoulder to variable degrees.In the first group, the scapulohumeral or glenohumeral joint is the anatomical joint mechanically linked to the physiological subdeltoid or suprahumeral joint (the "second shoulder joint") so that movements in the latter results in movements in the former. In the second group, the scapulocostal or scapulothoracic joint is the important physiological joint that cannot function without the two anatomical joints in the group, the acromioclavicular and sternoclavicular joints, i.e. the joints at both ends of the clavicle. Glenohumeral jointThe glenohumeral joint is the articulation between the head of the humerus and the glenoid cavity of the scapula. It is a ball and socket type of synovial joint. The glenohumeral joint allows for adduction, abduction, medial and lateral rotation, flexion and extension of the arm.Acromioclavicular jointThe acromioclavicular joint is the articulation between the acromion process of the scapula and the lateral end of the clavicle. It is a plane type of synovial joint. The acromion of the scapula rotates on the acromial end of the clavicle.Sternoclavicular jointThe sternoclavicular joint is the articulation of the manubrium of the sternum and the first costal cartilage with the medial end of the clavicle. It is a saddle type of synovial joint but functions as a plane joint. The sternoclavicular joint accommodates a wide range of scapula movements and can be raised to a 60° angle during elevation of the scapula.Scapulocostal jointThe scapulocostal joint (also known as the scapulothoracic joint) is a physiological joint formed by an articulation of the anterior scapula and the posterior thoracic rib cage. It is musculotendinous in nature and is formed predominantly by the trapezius, rhomboids and serratus anterior muscles. The pectoralis minor also plays a role in its movements. The gliding movements at the scapulocostal joint are elevation, depression, retraction, protraction and superior and inferior rotation of the scapula.Suprahumeral jointThe suprahumeral joint (also known as the subacromial joint) is a physiological joint formed by an articulation of the coracoacromial ligament and the head of the humerus. It is formed by the gap between the humerus and the acromion process of the scapula. This space is filled mostly by the subacromial bursa and the tendon of supraspinatus. This joint plays a role during complex movements while the arm is fully flexed at the glenohumeral joint, such as changing a lightbulb, or painting a ceiling.The Elbow - The human elbow is the summation of 3 articulations. The first 2 are the ones traditionally thought of as constituting the elbow: the humeroulnar articulation (the synovial hinge joint with articulation between the trochlea of the humeral condyle and the trochlear notch of the ulna) and the humeroradial articulation (the articulation between the capitulum of the humeral condyle and the concavity on the superior aspect of the head of the radius). The third is a pivot-type synovial joint with articulation between the head of the radius and the radial notch of the ulna.The wrist and Hand - There are 15 bones that form connections from the end of the forearm to the hand. The wrist itself contains eight small bones, called carpal bones. These bones are grouped in two rows across the wrist. The proximal row is where the wrist creases when you bend it. Beginning with the thumb-side of the wrist, the proximal row of carpal bones is made up of the scaphoid, lunate, and triquetrum. The second row of carpal bones, called the distal row, meets the proximal row a little further toward the fingers. The distal row is made up of the trapezium, trapezoid, capitate, hamate, and pisiform bones.The proximal row of carpal bones connects the two bones of the forearm, the radius and the ulna, to the bones of the hand. The bones of the hand are called the metacarpal bones. These are the long bones that lie within the palm of the hand. The metacarpals attach to the phalanges, which are the bones in the fingers and thumb.One reason that the wrist is so complicated is because every small carpal bone forms a joint with the bone next to it. This means that what we call the wrist joint is actually made up of many small joints.Articular cartilage is the material that covers the ends of the bones of any joint. Articular cartilage can be up to one-quarter of an inch thick in the large, weight-bearing joints. It is thinner in joints such as the wrist that don't support a lot of weight. Articular cartilage is white, shiny, and has a rubbery consistency. It is slippery, which allows the joint surfaces to slide against one another without causing any damage.The function of articular cartilage is to absorb shock and provide an extremely smooth surface to make motion easier. We have articular cartilage essentially everywhere that two bony surfaces move against one another, or articulate. In the wrist, articular cartilage covers the sides of all the carpals and the ends of the bones that connect from the forearm to the fingers.Hip and Pelvis - Your hip is the joint where your thigh bone meets your pelvis bone. Hips are called ball-and-socket joints because the ball-like top of your thigh bone moves within a cup-like space in your pelvis. The hip joint is a traditional ball and socket type of a joint, whereby the articulation of the hip bone, or femoral head, with the hip socket, or acetabulum, forms the hip joint. The hip bone fits snugly into the hip socket and allows for smooth, stable function.Femoral Head Articular Cartilage - Covering the end of the femoral head is a layer of smooth, fibrous tissue called articular cartilage, which allows for easy, almost friction-free movement of the femoral head within the acetabulum. This layer of articulating cartilage helps to stabilize loading across the hip joint.Acetabular Labrum - The acetabular labrum, which is a form of articular cartilage located deep within the hip socket, meshes with the articular cartilage covering the end of the femoral head and helps to increase overall stability and function of the entire hip joint. The acetabular labrum also helps to anchor the femoral head firmly into the acetabulum.Hip Joint Capsule - The hip joint capsule, which is a sheath of muscle encircling and enclosing the entire hip joint, helps to stabilize the hip joint and minimize the risk of hip joint dislocation when the hip joint is hyper-extended. The hip joint capsule also contains a series of tendons that serve to anchor various muscle attachments directly to the femoral head.The knee – The knee is the largest joint in the body and most frequently injured. It is a hinge joint and comprises of bones, cartilage, ligaments, tendons and muscles that work together to keep the knee functioning correctly.Bones
The knee joint provides the connection between the upper and lower bones of the leg. The primary bones that are part of the knee joint are the thighbone or femur, the two bones of the lower leg (the larger tibia shinbone on the inside of the leg and the smaller fibula bone on the outside of the leg) and the kneecap or patella.

CartilageThere are two types of cartilage in the knees: fibrocartilage and articular cartilage.

Articular cartilage covers the end of the femur, the top of the tibia and the back of the patella. This smooth, lubricated joint surface helps reduce friction between the bones during movement.

The fibrocartilage in the middle of the knee is the meniscus. There are two types of menisci: the medial and lateral. Both menisci are crescent-shaped pads of gristle-like material located between the tibia and femur on the outer and inner sides of each knee. They help absorb shock during motion and cushion the knee.

Ligaments
The bones in the knee are joined to the other bones by short bands of tough fibrous connective tissue called ligaments. They connect the femur and tibia and give the joint strength and stability.

There are four major ligaments in the knee: * The medial collateral ligament (MCL) runs alongside the inner part of the knee and limits side-to-side movement. * The lateral collateral ligament (LCL) runs alongside the outer part of the knee and limits side-to-side movement. * The anterior cruciate ligament (ACL) weaves inside the knee joint and limits rotation and forward movement of the tibia. * The posterior cruciate ligament (PCL) weaves inside the knee joint and limits backward movement of the tibia. The Foot and Ankle - The ankle joint is formed where the foot and the leg meet. The ankle, or talocrural joint, is a synovial hinge joint that connects the distal ends of the tibia and fibula in the lower limb with the proximal end of the talus bone in the foot. The articulation between the tibia and the talus bears more weight than between the smaller fibula and the talusBonesThe boney architecture of the ankle consists of three bones: the tibia, the fibula, and the talus. The articular surface of the tibia is referred to as the plafond. The medial malleolus is a boney process extending distally off the medial tibia. The distal-most aspect of the fibula is called the lateral malleolus. Together, the malleoli, along with their supporting ligaments, stabilize the talus underneath the tibia. The boney arch formed by the tibial plafond and the two malleoli is referred to as the ankle "mortise." The joint surface of all bones in the ankle are covered with articular cartilage.LigamentsThe ankle joint is bound by the strong deltoid ligament and three lateral ligaments: the anterior talofibular ligament, the posterior talofibular ligament, and the calcaneofibular ligament. * The deltoid ligament supports the medial side of the joint, and is attached at the medial malleolus of the tibia and connect in four places to the sustentaculum tali of the calcaneus, calcaneonavicular ligament, the navicular tuberosity, and to the medial surface of the talus. * The anterior and posterior talofibular ligaments support the lateral side of the joint from the lateral malleolus of the fibula to the dorsal and ventral ends of the talus. * The calcaneofibular ligament is attached at the lateral malleolus and to the lateral surface of the calcaneus.Though it does not span across the ankle joint itself, the syndesmotic ligament makes an important contribution to the stability of the ankle. This ligament spans the syndesmosis, which is the term for the articulation between the medial aspect of the distal fibula and the lateral aspect of the distal tibia.3i – Describe the movements of the major joints of the body Major Joint | Joint Movement | Shoulder | The shoulder joint has the following normal ranges of movement: Flexion, Extension, Adduction, Abduction and Medial Rotation. | Shoulder girdle | The shoulder girdle has the following normal ranges of movement: Elevation, Depression, Adduction and Abduction. | Elbow | The elbow joint has the following normal ranges of movement: Flexion, Extension, Pronation and Supination. | Wrist & Hand | The wrist joint has the following normal ranges of movement: Flexion, Extension, Adduction, Abduction and Circumduction. | Hip & Pelvis | The hip joint has the following normal ranges of movement: Flexion, Extension, Adduction, Abduction, Medial Rotation and Lateral Rotation. | Knee | The knee joint has the following normal ranges of movement: Flexion and Extension | Foot & Ankle | The ankle joint has the following normal ranges of movement: Plantar Flexion, Dorsi Flexion, Inversion and Eversion. | The Spinal Column | The vertebral column has the following normal ranges of movement: Flexion, Extension, Lateral Flexion and Rotation. |
3j – Describe the positions, actions and attachment sites of the major musclesMuscles of the shoulder Muscle | Origin | Insertion | Action | Sternocleidamastoid | Sternum & Clavicle | Mastoid Process | Flex and side bend head | Scalenes | C2-C7 transverse process | 1st and 2nd rib | Flex and rotate head. Raise ribs | Trapezius | Occipital, C7-T3, T3-T12 | Lateral third of clavicle. Clavicle, acromium and Spine of Scapula | Stabilises the scapula. Pull scapula towards spine, some elevation, rotation and adduction. Upper part can also extend and rotate the neck | Deltoid | Lateral clavicle, acromiom, spin of scapula | Deltoid tuberosity of humerus | Draw arm forward and back, inwardly rotate and abduct arm. | Infraspinatus | Lower posterior surface of scapula | Great tuberosity of humours | Outwardly rotate arm | Supraspinatus | Upper posterior Surface of scapula | Great tuberosity of humerus | Initiates shoulder abduction | Teres Major | Lower lateral border of scapula | Medial lip of bicipital groove of humerus | Adduct, extend and inwardly rotate arm | Teres Minor | Lateral border of scapula | Great tuberosity of humerus | Outwardly rotate arm | Rhomboids | C6-C7, T1-T4 spinous processes | Medial border of the scapula | Brace and rotate the scapula and pull it towards the spine | Subscapularis | Anterior surface of scapula | Lesser tuberosity of humerus | Inwardly rotate arm | Latissimus Dorsi | T7-T12, and via lumbar fascia to L1-L5 and iliac crest | Bicipital grove of the humerus | Adduct, draw back (extend) and inwardly rotate arm | Pectoralis Major | Clavicle, sternum, 1st to 6th ribs | Lateral lip of biciptal groove of humerus | Horizontal adduction, adduct, flex and inwardly rotate arm | Pectoralis Minor | 3rd to 5th ribs | Coracoid process of scapula | Draw scapula forward and down | Serratus Anterior | Lateral surface of 1st to 9th ribs | Anterior surface of medial border of scapula | Pull scapula forward (protract) and rotate it | Levator Scapular | C1-C4 transverse processes | Superior angle of scapula | Raise scapula or rotate and sidebend head | Coracobrachialis | Coracoid process of scapula | Medial border or humerus | Draw arm forward and inward |
Muscles of the Upper Limb Muscle | Origin | Insertion | Action | Biceps Brachii | Coracoid process of scapula Long head; passes over top of joint laterally to scapula | Via strong tendon to radial tuberosity and bicipital aponeurosis | Strong flexor and supinator of forearm Weak: abduct (long head) and adduct (short head) the shoulder | Triceps Brachii | Long head: infraglenoid tubercle of scapula. Medial & lateral heads: posterior surface of humerus | Through a flat tendon to olecranon process of ulna | Extend elbowLong head: slight adduction of shoulder | Brachialis | Lower anterior surface of humerus | Ulnar tuberosity | Flex elbow | Brachioradialis | Distal, lateral edge of humerus | Styloid process of radius | Flex forearm | Pronator Teres | Above the medial epicondyle | Midway along lateral radius | Pronate and flex forearm |
Muscles of the Anterior Trunk Muscle | Origin | Insertion | Action | External Obliques | Lateral surface of 5th-12th ribs (running diagonally downwards) | Abdominal aponeurosis and lower 3 ribs and iliac crest | Rotate, flex and side bend trunk. Support viscera and assist exhalation. | Internal Obliques | Iliac crest and thoracolumbar fascia and inguinal ligament (mostly running diagonally upward) | | | Rectus Abdominus | Pubic crest | Cartilage of 5th-7th ribs and xiphoid process | Flex trunk | Transverse Abdominus | Anterior two thirds of iliac crest. Lateral third of inguinal ligament. Costal cartilages of lower 6 ribs. Thoracolumbar fascia. | Linea alba via an abdominal aponeurosis. | Compress abdomen, helping to support the abdominal viscera against the pull of gravity. | Diaphragm | Sternum, xiphoid process, costal cartilage, 7th-12th ribs and L2-3 | Central tendon | Inhalation; the upwardly domed muscle is drawn downward creating a vacuum in the chest cavity | Intercostals | Cross between adjacent ribs | Internal; forced exhalation External; inhalation |
Muscles of the Posterior Trunk Muscle | Origin | Insertion | Action | Quadratus Lumborum | Iliac crest and iliolumbar ligament | 12th rib, L1-L4/5 transverse processes | Unilaterally; side bend trunk and bilaterally; extends lower back | Multifidis | Sacrum and transverse processes of all vertebrae, from C4 | Spinous processes 2 to 4 vertebrae above | Intervertebral movements; extension, side bending and rotation | Erector Spinae | Slips of muscles arising from the sacrum. Iliac crest. Spinous and transverse processes of vertebrae. Ribs. | Ribs. Transverse and spinous processes of vertebrae. Occipital bone. | Extends and laterally flexes vertebral column. Helps maintain correct curvature of spine in the erect and sitting positions. Steadies the vertebral column on the pelvis during walking. |
Muscles of the lower Limb Muscle | Origin | Insertion | Action | Psoas | T12-L4/5 transverse processes, vertebral bodies and discs | Lessor trochanter | Flex hip | Iliacus | Anterior, inferior iliac spine and iliac fossa | | | Gluteus Maximus | Medial iliac crest, sacrum, coccyx and sacrotuberous ligament | Proximal part; iliotibial bandDistal part; gluteal tuberosity of femur | Extend and outwardly rotate hip, extend trunk. Proximal part; slight abduction Distal part; slight adduction | Gluteus Medius | Upper posterior of ilium | Great trochanter of femur | Anterior; flex and inwardly rotate hip Posterior; extend and outwardly rotate hip | Gluteus Minimus | Lower posterior surface of ilium | | | Piriformis | Anterioir lateral surface of sacrum | Great trochanter of femur | Outwardly rotate and abduct hip | Pectineus | Upper pubis | Linea aspera of femur | Adduct and flex hip, and slight inward roatation | Quads– Rectus Femoris | Anterior, inferior iliac spine | Via patella and patella tendon to tibial tuberosity | Flex hip and extend knee | Quads- Vastus Lateralis | Upper part of femur | Patella border and patella ligament to tibial tuberosity | Extend knee | Quads –Vastus Medialis | | | | Quads – Vastus Intermedius | | | | Sartorius | Anterior superior iliac spine (ASIS) | Upper, medial tibial shaft | Flex hip and knee, outwardly rotate and abduct hip, inwardly rotate knee | Hams – Bicep Femoris | Long head; ischial tuberosity Short head; upper femur | Lateral tibial condyle and lateral head of fibula | Flex knee, outwardly rotate it when flexed, and extend hip | Hams – Semitendinosus | Ischial tuberosity | Medial tibial condyle | Flex knee, inwardly rotate it when flexed, and extend hip | Hams – Semimembranosus | | | | Tensor Fasciae Latae | Anterior iliac crest | Via Iliotibial band to lateral tibial condyle | Abduct hip and slight flexion and inward rotation | Adductors – Longus | From pubis to ischium | Length of medial border of femur | Adduct leg and slight outward rotation | Adductors – Brevis | | | | Adductors – Magnus | | | | Gracilis | Lower pubis | Upper, medial tibial shaft | Adduct leg and flex knee | Gastrocnemius | Posterior, medial and lateral femoral condyles | Via Achilles tendon to posterior calcaneum | Plantaflex foot and flex knee | Soleus | Head and upper third of posterior tibia and fibula | | Plantaflex foot | Tibialis Anterior | Lateral surface of tibia and interosseus membrane | Plantar surface of 1st metatarsal and medial cuneiform | Dorsiflex foot and slight supination | Tibialis Posterior | Interosseus membrane and adjacent surfaces of tibia and fibula | Plantar side of tarsals, 2nd – 4th metatarsals and calcaneum | Plantaflex and invert foot | Peroneus Longus | Head and lateral aspect of fibula | Base of 1st metatarsal and medial cuneiform | Pronate foot and assist plantaflexion | Extensor Hallucis Longus | Fibula and interosseus membrane | Distal phalanx of big toe | Extend and dorsiflex big toe, and supinate foot | Flexor Hallucis Longus | Posterior surface of lower two thirds of fibula | Distal phalanx of big toe | Plantaflex and invert foot and big toe | Extensor Digitorum Longus | Lateral tibial condyle and head of fibula | 2nd to 5th toes | Dorsiflex foot and toes | Flexor Digitorum Longus | Upper posterior surface of tibia | Distal phalanx of 4 outer toes | Plantaflex foot and toes, invert foot |
3k – Explain the structure and functions of vertebral column and thorax The vertebral column is commonly referred to as the spine and is made up of 7 cervical vertebrae, 12 thoracic and 5 lumbar. In addition the sacrum consists of 5 vertebrae fused together and the coccyx is 3-4 vertebrae fused together. The spine houses and protects the spinal cord and nerve roots, provides the body with structural support /stability and gives the muscles of the torso bony attachment points. The vertebral column helps the body to distribute body weight evenly, allows for absorption of impact and allows flexibility and mobility. The thorax houses the main organs of the body, including the heart and lungs and these are protected by the bony structures of the ribs and spine. Like other bones in the body, the vertebrae produce red blood cells, and are a source of mineral storage. 3l – Explain the arches of the footThe arches of the foot are formed by the tarsal and metatarsal bones and, strengthened by ligaments and tendons, allow the foot to support the weight of the body in the erect posture with the least weight. The arches also provide leverage and shock absorption. The arches are categorized as transverse and longitudinal arches of the foot.The Longitudinal arch of the foot can be broken down into several smaller arches: The main arches are the antero-posterior arches, which may, for descriptive purposes, be regarded as divisible into two types—a medial and a lateral. Medial archThe medial arch is made up by the calcaneus, the talus, the navicular, the three cuneiforms, and the first, second, and third metatarsals. Its summit is at the superior articular surface of the talus, and its two extremities or piers, on which it rests in standing, are the tuberosity on the plantar surface of the calcaneus posteriorly and the heads of the first, second, and third metatarsal bones anteriorly. The chief characteristic of this arch is its elasticity, due to its height and to the number of small joints between its component parts. Lateral archThe lateral arch is composed of the calcaneus, the cuboid, and the fourth and fifth metatarsals. Its summit is at the talocalcaneal articulation, and its chief joint is the calcaneocuboid, which possesses a special mechanism for locking, and allows only a limited movement. The most marked features of this arch are its solidity and its slight elevation; two strong ligaments, the long plantar and the plantar calcaneocuboid, together with the Extensor tendons and the short muscles of the little toe, preserve its integrity. Fundamental longitudinal archWhile these medial and lateral arches may be readily demonstrated as the component antero-posterior arches of the foot, yet the fundamental longitudinal arch is contributed to by both, and consists of the calcaneus, cuboid, third cuneiform, and third metatarsal: all the other bones of the foot may be removed without destroying this arch. Transversal archIn addition to the longitudinal arches the foot presents a series of transverse arches. At the posterior part of the metatarsus and the anterior part of the tarsus the arches are complete, but in the middle of the tarsus they present more the characters of half-domes the concavities of which are directed downward and medialward, so that when the medial borders of the feet are placed in apposition a complete tarsal dome is formed. The transverse arches are strengthened by the interosseous, plantar, and dorsal ligaments, by the short muscles of the first and fifth toes (especially the transverse head of the Adductor hallucis), and by the Peronæus longus, whose tendon stretches across between the piers of the arches.5a – Explain the structure and function of neurones and nerves Neuron structureThe nervous system contains two types of cells: neurons and neuroglial cells. Neurons are the cells that receive and transmit signals. The neuroglial cells are the support systems for the neurons — the neuroglial cells protect and nourish the neurons.Each neuron contains a nerve cell body with a nucleus and organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Branching off the nerve cell body are the dendrites, which act like tiny antennae picking up signals from other cells. At the opposite end of the nerve cell body is the axon, which is a long, thin fiber with branches at the end that sends signals. The axon is insulated by a myelin sheath made up of segments called Schwann cells. Nerve impulses are received by the dendrites, travel down the branches of the dendrites to the nerve cell body, and are carried along the axon.Neuron FunctionNeurons send signals to other cells as electrochemical waves travelling along thin fibers called axons, which cause chemicals called neurotransmitters to be released at junctions called synapses. A cell that receives a synaptic signal may be excited, inhibited, or otherwise modulated.Nerve Structure Nerves, are cylindrical bundles of fibers that emanate from the brain and central cord, and branch repeatedly to innervate every part of the body. A microscopic examination shows that nerves consist primarily of the axons of neurons, along with a variety of membranes that wrap around them and segregate them into fascicles.Nerve Function Basically, a nerve is a fibre that connects the brain and spinal cord with various parts of the body (aka - receptor organs). Nerves conduct impulses from the brain/spinal cord to these receptor organs as well as conducting impulses from the receptor organs back to the brain/spinal cord.
5b- Outline the divisions of the nervous systemAll the divisions of the nervous system are based universally on the functions of neurons. Neurons are specialized cells that process information. Like all cells, they are unbelievably complicated in their own right. All nervous systems have four basic types of functional cells: * Sensory neurons: These neurons tell the rest of the brain about the external and internal environment. * Motor (and other output) neurons: Motor neurons contract muscles and mediate behavior, and other output neurons stimulate glands and organs. * Communication neurons: Communication neurons transmit signals from one brain area to another. * Computation neurons: The vast majority of neurons in vertebrates are computation neurons. Computation neurons extract and process information coming in from the senses, compare that information to what’s in memory, and use the information to plan and execute behavior. Each of the several hundred brain regions contain very approximately several dozen distinct types of computational neurons that mediate the function of that brain area.5c – Describe the structure and functions of the central nervous system (CNS)The nervous system is an organ system containing a network of specialized cells called neurons that coordinate actions and transmit signals between different parts of its body. The nervous system consists of two parts, central and peripheral. The central nervous system contains the brain, spinal cord, and retina. The central nervous system (CNS) is the largest part, and includes the brain and spinal cord. The spinal cavity contains the spinal cord, while the head contains the brain. The CNS is enclosed and protected by meninges, a three-layered system of membranes, including a tough, leathery outer layer called the dura mater. The brain is also protected by the skull and the spinal cord by the vertebrae.At the most basic level, the function of the nervous system is to send signals from one cell to others or from one part of the body to others. There are multiple ways that a cell can send signals to other cells. One is by releasing chemicals called hormones into the internal circulation, so that they can diffuse to distant sites. In contrast to this "broadcast" mode of signaling, the nervous system provides "point-to-point" signals—neurons project their axons to specific target areas and make synaptic connections with specific target cells. Thus, neural signaling is capable of a much higher level of specificity than hormonal signaling. It is also much faster: the fastest nerve signals travel at speeds that exceed 100 meters per second.At a more integrative level, the primary function of the nervous system is to control the body. It does this by extracting information from the environment using sensory receptors, sending signals that encode this information into the central nervous system, processing the information to determine an appropriate response, and sending output signals to muscles or glands to activate the response. The evolution of a complex nervous system has made it possible to have advanced perception abilities such as vision, rapid coordination of organ systems, and integrated processing of concurrent signals. The sophistication of the nervous system makes it possible to have language, abstract representation of concepts, transmission of culture, and many other features that would not exist without the human brain.5d – Describe the structure and functions of the peripheral nervous system (PNS)The peripheral nervous system (PNS, or occasionally PeNS) consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system (CNS) to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain barrier, leaving it exposed to toxins and mechanical injuries. There are two types of cells in the peripheral nervous system. These cells carry information to (sensory nervous cells) and from (motor nervous cells) the central nervous system (CNS). Cells of the sensory nervous system send information to the CNS from internal organs or from external stimuli.

Motor nervous system cells carry information from the CNS to organs, muscles, and glands. The motor nervous system is divided into the somatic nervous system and the autonomic nervous system Simplified schema of basic nervous system function: signals are picked up by sensory receptors and sent to the spinal cord and brain, where processing occurs that results in signals sent back to the spinal cord and then out to motor neurons5e – Describe the structure and functions of the autonomic nervous systemThe autonomic nervous system is a division of the peripheral nervous system, which is a subdivision on the nervous system as a whole. which also included the central nervous system.

The autonomic division is responsible for involuntary processes in the body, such as maintaining blood pressure, heart rate, respiration, digestion, and other metabolic processes that contribute to homeostasis.

The prime ruler of the autonomic nervous system (ANS) is the hypothalamus which is located above the pituitary gland. The hypothalamus is also known as the Master glad
The sympathetic and the parasympathetic nervous system are parts of what is commonly called the autonomic nervous system. (Autonomic = cannot be controlled by the mind). You can say that these systems work in balance with each other and directly or indirectly affect almost every structure in the body. The sympathetic nervous system has an active "pushing" function, the parasympathetic has mainly a relaxing function. The sympathetic nervous system is located to the sympathetic chain, which connects to skin, blood vessels and organs in the body cavity. The sympathetic chain is located on both sides of the spine and consists of ganglias. The autonomic nervous system is most important in two situations: emergency situations that cause stress and require us to "fight" or take "flight", and nonemergency situations that allow us to "rest" and "digest". The autonomic nervous system also acts in "normal" situations to maintain normal internal functions and works with the somatic nervous system.6a – Explain the components and functions of the blood Blood is made up of red cells, white cells, plasma, and platelets. The functions of each are: * Red cells- Carries oxygen to and carbon dioxide from cells in the body. * White cells- Defend your body from germs, viruses, and bacteria * Plasma- Carries nutrients and suspends the other 3 components * Platelets- Very important for clotting blood and repairing vessel walls
6b – Describe the structure of the heart The human heart has a mass of between 250 and 350 grams and is about the size of a fist. It is enclosed in a double-walled protective sac called the pericardium. The double membrane of pericardium consist of the pericardial fluid which nourishes the heart and prevents from shocks. The superficial part of this sac is called the fibrous pericardium. The fibrous pericardial sac is itself lined with the outer layer of the serous pericardium (known as the parietal pericardium). This composite (fibrous-parietal-pericardial) sac protects the heart, anchors its surrounding structures, and prevents overfilling of the heart with blood. The inner layer also provides a smooth lubricated sliding surface within which the heart organ can move in response to its own contractions and to movement of adjacent structures such as the diaphragm and lungs.The outer wall of the human heart is composed of three layers. The outer layer is called the epicardium, or visceral pericardium since it is also the inner wall of the (serous) pericardium. The middle layer of the heart is called the myocardium and is composed of muscle which contracts. The inner layer is called the endocardium and is in contact with the blood that the heart pumps. Also, it merges with the inner lining (endothelium) of blood vessels and covers heart valves. The human heart has four chambers, two superior atria and two inferior ventricles. The atria are the receiving chambers and the ventricles are the discharging chambers.The pathways of blood through the human heart is part of the pulmonary and systemic circuits. These pathways include the tricuspid valve, the mitral valve, the aortic valve, and the pulmonary valve. The mitral and tricuspid valves are classified as the atrioventricular (AV) valves. This is because they are found between the atria and ventricles. The aortic and pulmonary semi-lunar valves separate the left and right ventricle from the pulmonary artery and the aorta respectively. These valves are attached to the chordae tendinae (literally the heartstrings), which anchors the valves to the papilla muscles of the heart.The interatrioventricular septum separates the left atrium and ventricle from the right atrium and ventricle, dividing the heart into two functionally separate and anatomically distinct units.6c – Explain pulmonary and systemic circulation Blood flows through the heart in one direction, from the atria to the ventricles, and out of the great arteries, or the aorta for example. Blood is prevented from flowing backwards by the tricuspid, bicuspid, aortic, and pulmonary valves.Pulmonary circulation is the half portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated (oxygen-rich) blood back to the heart.The heart acts as a double pump. The function of the right side of the heart is to collect de-oxygenated blood, in the right atrium, from the body (via superior and inferior vena cavae) and pump it, via the right ventricle, into the lungs so that carbon dioxide can be dropped off and oxygen picked up (gas exchange). This happens through the passive process of diffusion. Systemic circulation is the part of the cardiovascular system which carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heartThe left side (see left heart) collects oxygenated blood from the lungs into the left atrium. From the left atrium the blood moves to the left ventricle which pumps it out to the body (via the aorta).On both sides, the lower ventricles are thicker and stronger than the upper atria. The muscle wall surrounding the left ventricle is thicker than the wall surrounding the right ventricle due to the higher force needed to pump the blood through the systemic circulation. Atria facilitate circulation primarily by allowing uninterrupted venous flow to the heart, preventing the inertia of interrupted venous flow that would otherwise occur at each ventricular systole6d – Explain the cardiac conduction system and cardiac cycle Cardiac Cycle The cardiac cycle is a term referring to all or any of the events related to the flow or blood pressure that occurs from the beginning of one heartbeat to the beginning of the next. The frequency of the cardiac cycle is described by the heart rate. Each beat of the heart involves five major stages. The first two stages, often considered together as the "ventricular filling" stage, involve the movement of blood from atria into ventricles. The next three stages involve the movement of blood from the ventricles to the pulmonary artery (in the case of the right ventricle) and the aorta (in the case of the left ventricle).Cardiac cycle is broken down into three phases : * Diastole * Relaxation/passive filling phase lasting 0.5 seconds. * Deoxygenated blood enters right atria from superior and inferior vena cavae. * Oxygenated blood enters left atrium from pulmonary veins. * Rising pressure of blood against AV valves forces blood through into ventricles. * Past tricuspid valve on the right side of the heart. * Past bicuspid valve on the left side of the heart. * Volume of blood after filling is termed End Diastolic Volume (EDV). * Atrial systole * Contraction of left and right atria. * Increased pressure in atria forces the remaining blood into the left and right ventricles. * Ventricular systole * Contraction of both left and right ventricles. * Increases ventricle pressure forcing blood out of both ventricles (Stroke volume). * Right ventricle forces blood out of pulmonary valve into pulmonary artery to the lungs. * Left ventricle forces blood out of aortic valve into aorta to the body tissues. * A reserve volume of blood may be left in ventricles (ESV). * Tricuspid and bicuspid valves remain shut. * Aortic and pulmonary valve closeCardiac Conduction system controls the cardiac cycle The normal intrinsic electrical conduction of the heart allows electrical propagation to be transmitted from the Sinoatrial Node through both atria and forward to the Atrioventricular Node. Normal/baseline physiology allows further propagation from the AV node to the ventricle or Purkinje Fibers and respective bundle branches and subdivisions/fascicles. Both the SA and AV nodes stimulate the Myocardium. Time ordered stimulation of the myocardium allows efficient contraction of all four chambers of the heart, thereby allowing selective blood perfusion through both the lungs and systemic circulation.The process is as follows : * SA node/pacemaker in right atria wall initiates cardiac impulse. * Travels through walls of L/R atria causing atria to contract = atria systole. * Impulse passes to atrioventricular (AV) node. * Impulse conducted down Bundle of His and into L/R Purkinje fibres to apex of heart. * Impulse travels up and around ventricle walls, causing ventricles to contract = ventricular systole. * Heart returns to diastole/relaxed phase. * Atria begin to fill with blood.6e – Define the key cardiovascular variables Key cardiovascular variables include: * Cardiac Output * Stroke volume * Heart Rate (pulse) * Blood pressure Variables differ from person to person as humans are unique. 7a – Describe the Structure of the respiratory system As air is inhaled and passes through the nasal passages, it is filtered, heated and humidified. The filtering process continues as air flows down through the pharynx, larynx, trachea and bronchi to the lungs. Each lung contains a tree of branching tubes that end in tiny air sacs, or alveoli, where gases diffuse into and out if the bloodstream through tiny vessels. Nasal Cavity – A sticky mucous membrane lines the nasal cavity and traps foreign particles; surface hairs called cilia move the particles towards the nose to be sneezed out. Pharynx – The pharynx, or throat, has three parts. The upper part allows the passage of air only; lower parts permit the passage of foods and liquids; these are known as the nasopharynx, oropharynx and laryngopharynx.Epiglottis – This flap of cartilage stops food from entering the trachea. Larynx – The larynx, or voice box, lies between the pharynx and the trachea. It is composed of areas of cartilage and connective tissue. At the entrance to the larynx, there is a leaf shaped flap of cartilage called the epiglottis. This structure remains upright to allow the passage of air but tips back during swallowing to close the larynx and prevent food from entering the trachea. The vocal chords that stretch across the larynx are responsible for the production of speech. Trachea – The main airway to the lungs, the trachea, divides into two large primary bronchi, which channel air to the right and left lung. Bronchi – The two primary bronchi, one to each lung, branch into progressively smaller airways. Secondary Bronchus – The five secondary, or lobar, bronchi are branches if the primary bronc. Each supplies an individual lobe. Tertiary bronchus – These branches of the five lobar (secondary) bronchi are also called segmental bronchi because each one aerates an individual segment within each lobe. They may further divide into 50-80 terminal bronchioles. Terminal Bronchiole – These tiny bronchioles – about 30,000 in each lung – are the terminal ends of the segmental bronchi. They divide into two or more respiratory bronchioles that lead into the alveoli via alveolar ducts.Alveoli – The air sacs of the lungs, called alveoli, are elastic, thin walled structures that are supplied with air by the respiratory bronchioles. Tiny blood capillaries surrounding the alveolar walls allow oxygen to be carried into the bloodstream. In exchange, carbon dioxide waste diffuses from the blood into the alveoli, from where it is exhaled. White blood cells, called macrophages, on the inner surface of each alveolus trap and destroy inhaled bacteria and fine particles.Lobes of the lung – The right lung is separated by surface fissures into three lobes, while the smaller left lung is divided into only two lobes. Each lobe is subdivided into segments. Diaphragm – This dome shaped muscle separates the chest cavity from the abdominal cavity. It contracts and flatterns during inhalation, creating space for air intake. It relaxes as air is expelled. 7b – Explain the function of the respiratory systemTo function, body cells need oxygen. The respiratory system, which consists of air passages, pulmonary vessels, the lungs and breathing muscles such as the diaphragm and the intercostals, these supply fresh oxygen to the blood for distribution to the rest of the body tissues. In addition, respiration removes carbon dioxide, a waste product of body processes. 8a – Outline the functions of the lymphatic systemThe healthy body has an internal defence mechanism known as the immune system, which guards against invasion by disease-causing organisms and is also activated by cancerous changes in cells. This system is based on specialised white cells called lymphocytes, which respond to infection or cell abnormalities in a number of different ways. The lymphatic system is also responsible for the distribution of fluid throughout the body and transportation of fats. The lymphatic system is part of the body’s immune system, which provides defence against disease-causing organisms. 8b – Explain the structures of that make up the lymphatic systemLymph Node Structure – are small masses of tissue enclosed in a fibrous capsule. They range in size from1-20mm and within each node are cavities (sinuses) containing two types of white blood cells: Lymphocytes and Macrophages. These cells play a major role in defending the body against infection. The structure of the lymph node includes: * Capsule – Lymph nodes are composed of lymph tissue enclosed in a fibrous capsule made of collagen and elastin (types of protein) * Afferent Lymph Vessel – These are vessels that transport lymph to the node. * Efferent Lymph Vessel – This is a single vessel that carries filtered lymph away from the node. * Sinus – Channels within the sinuses slow down the flow of lymph so that macrophages can ingest bacteria and debris. * Trabeculum – Fibrous supporting structures called trabeculae, divide the node into segments * Germinal Centre – When infection occurs, the germinal centres release activated lymphocytes. These move towards the surface of the node becoming plasma cells that produce antibodies. * Reticular fibres – A meshwork of fibres helps to support cells in the nodeLymph – Is a watery fluid that leaks out of the blood vessels and accumulates in the spaces between the cells of body tissues. This fluid drains into a network of lymph capillaries and then into larger vessels known as lymphatics, which are studded with filters called nodes. Lymph from most tissues filters through at least one node before returning to the bloodstream. Bone Marrow – The lymphocytes begin life as stem cells in the bone marrow. Also generated here are monocytes, the largest of the white blood cells. These migrate from the blood into tissue spaces where they develop into scavenger cells called macrophages that ingest bacteria and dead cells. Lymph Nodes in the Head & Neck – The lacrimal gland produces tears that contain a protective enzyme. The tonsils and adenoid glands produce antibodies that fight against ingested or inhaled organisms. In addition to these glands, there are also occipital, submandibular, cervical and auricular glands. Lymph Nodes in the Body – Within the body there are axillary nodes, located in the upper are toward the armpit, abdominal lymph nodes, including the lateral aortic, internal iliac and common iliac nodes. Around the knee area the popliteal nodes are located, these drain excess lymph from the legs and feet. Spleen – This is the largest of the lymph organs. It produces antibodies and filters our damaged red blood cells. Thymus – Important lymphocytes called T cells mature in the thymus. The thymus is located under the breastbone in the top portion of the chest. The gland is pinkish gray, spongy and flat.Subclavian Veins – Lymph drains from the upper right part of the body into the right subclavian vein. While lymph from the rest of the body collects in the thoracic duct, draining from here into the left subclavian vein. Cisterna Chyli – Lymphatics form the lower body converge to form this vessel. Lymph Capillaries – The lymph circulation system is not a closed circuit; instead capillaries start as blind ended sacs within tissue spaces before joining larger lymphatics Lymphatics - From the lymph capillaries, lymph flows into the lymphatics: as the diameter of the vessels increases, the walls become thicker. In the tissue just below the skin, these vessels roughly parallel the path of veins. In the organs, they follow arteries and may form networks around them. 9a – Describe the structures that make up the digestive system. The mouth, pharynx, oesophagus, stomach, small intestine, large intestine, rectum, and anus make up the digestive tract, which is basically a food-processing pipe about 9m (30ft) long. Associated digestive structures include three pairs of salivary glands, the pancreas, the liver and the gallbladder, each of which has an important role. The appendix – a short, blind ended tube attached to the large intestine – has no known function. Food is moved through the digestive tract by muscular contractions called peristalsis. The Mouth – Food enters the digestive system through the mouth and is cut, crushed and ground by the teeth. The muscular tongue moves food in the mouth. Pharynx – When food is swallowed it travels down the pharynx or throat, into the oesophagus. Salivary Glands – Saliva secreted by these glands lubricates food and contains enzymes that start digestion. Oesophagus – This thick-walled, muscular tube connects the pharynx with the stomach. Liver – This large organ processes absorbed nutrients, detoxifies harmful substances, and produces bile. Stomach – This J-shaped muscular bag churns, digests, and stores food. Gallbladder – Bile produced by the liver is stored here. Small Intestine – This is the major site of digestion and absorption of nutrients. Large Intestine – This part of the digestive tract absorbs most of the remaining water from food residue, and forms faeces. Rectum – Faeces pass into the rectum and are eliminated from the body via the anus. Anus – The digestive tract ends at this body opening. 9b Explain the processes of digestion and absorptionThe digestive process breaks down food by chemical and mechanical action into substances that can pass into the bloodstream and be distributed to the body cells. Certain nutrients, such as salts and minerals can be absorbed directly into the circulation. Fats, complex carbohydrates and proteins are broken down into smaller molecules before being absorbed. 1 – Mouth & Oesophagus Food is chewed with the teeth and mixed with saliva. The enzyme amylase, present in saliva begins the breakdown of starch into sugar. Each lump of soft food, called bolus, is swallowed and propelled by contractions down the oesophagus to the stomach. 2 – Stomach Pepsin is an enzyme produces when pepsinogen, a substance secreted by the stomach lining, is modified by hydrochloric acid (also produced by the stomach lining). Pepsin breaks down proteins into smaller units called polypeptides and peptides. Lipase is a stomach enzyme that breaks down fatty acids. Thenacid produces by the stomach also kills bacteria. 3 – Duodenum Lipase, a pancreatic enzyme, breaks down fats into glycerol and fatty acids. Amylase, another enzyme produced by the pancreas, breaks down starch into maltose, a disaccharide sugar. Trypsin and chymotrypsin are powerful pancreatic enzymes hat split proteins into polypeptides and peptides. 4 – Small Intestine Maltose, sucrase, and lactase, are enzymes produced by the lining if the small intestine. They convert disaccharide sugars into monosaccharide sugars. Peptidase, another enzyme produced in the intestine, splits large peptides into smaller peptides and then into amino acids. 5 – Large Intestine Undigested food enters the large intestine, where water and salt are absorbed by the intestinal lining. The residue, together with waste pigments, dead cells, and bacteria, is pressed into faeces and stored for excretion.10a – Describe the structure of urinary system The urinary system, also known as the urinary tract, consists of two kidneys, ureters, the bladder, and the urethra. Waste products are for filtered form the blood by the kidneys for excretion in the urine. From the kidneys, urine passes down two tubes, the ureters, to the hollow bladder. Urine is stored in the bladder until a convenient time, when the muscles at the bladder outlet relax, allowing the urine to be expelled from the body through the urethra. 10b – Explain the functions of the kidneys Each kidney is about 10-12.5cm (4-5inches) long, and contains about one million filtering units. The kidney participates in whole-body homeostasis, regulating acid-base balance, electrolyte concentrations, extracellular fluid volume, and regulation of blood pressure. The kidney accomplishes these homeostatic functions both independently and in concert with other organs, particularly those of the endocrine system. Many of the kidney's functions are accomplished by relatively simple mechanisms of filtration, re-absorption, and secretion. 10c – Explain the functions of the ureters, bladder and urethra Bladder - To hold urine The bladder is a sort of pouch found in the end of the genito-urinarian tract. Its function is to retain the urine of the body until it can be released to the urethra and out of the body. Ureters - The ureters are the thick, long 'tubes' that aid the urine in moving from the kidneys to the bladder. They are about 10 to 12 inches in length and the urine moves downward by gravity and peristalsis (waves of contractions). The ureters enter the urinary bladder at an angle to help prevent any back flow (reflux) of urine back into the ureter.Urethra - The urethra carries urine (from the bladder) out of the body, and in males it also carries semen from the testes through the penis (for sexual ejaculation). In both men and women, the urethra is the tube through which urine is excreted from the urinary bladder to outside the body. Urine flows from the bladder out of the body by way of the urethra when the sphincter muscle is relaxed. The urethral sphincter muscle is at the base of the bladder and controls the release of urine from the bladder into the urethra, which then flows out of the meatus (opening at the end of the urethra) when urinating. 11a – Explain the structure and functions of the endocrine glands The endocrine system is a collection of hormone producing glands and cells located in various parts of the body, such as the pancreas and the ovaries. Hormones are complex chemical substances that are secreted into the bloodstream and regulate body functions such as metabolism, growth, and sexual reproduction. Hypothalamus – Most hormones for this cluster of nerve cells at the base of the brain stimulate other glands to produce their own hormones. Pituitary Gland – The pituitary gland, sometimes called the “master gland” controls the activities of many other endocrine glands and cells. This pea-sized structure hangs from the base of the brain; it is attached by a short stalk of nerve fibres to the hypothalamus, a brain area that controls pituitary function. The pituitary has two lobes, anterior and posterior, which produce a range of hormones. The secretions from the endocrine gland control the other endocrine glands and influence growth, metabolism, and maturation.
Pineal Gland - The pineal gland is a pine cone shaped gland of the endocrine system. A structure of the diencephalon of the brain, the pineal gland produces several important hormones including melatonin. Melatonin influences sexual development and sleep-wake cycles. The pineal gland is composed of cells called pinealocytes and cells of the nervous system called glial cells. The pineal gland connects the endocrine system with the nervous system in that it converts nerve signals from the sympathetic system of the peripheral nervous system into hormone signals.Thyroid Gland – The thyroid gland, which is situated at the font f the neck partially surrounding the trachea, plays an important role in regulating the body’s metabolism. At the back of this gland are the four parathyroid glands, which regulate calcium levels in blood, the hormone they secrete acts on bones to release stored calcium, and on the kidneys to increase production of vitamin D, which in turn increases the body’s calcium absorption. Adrenal Glands – The adrenal glands are small triangular structures located on top of each kidney. They consist of two distinct parts; an outer layer known as the cortex and the inner region called the medulla. The cortex secretes a group of hormones that influence the body’s metabolic processes; the medulla releases hormones that affect the body’s response to stress, commonly known as “fight – or – flight”. Pancreas – The pancreas has a dual function. A major part of its tissues produces digestive enzymes; within these tissues are small clusters of hormone-producing cells known as islets of Langerhans. Each cell cluster contains alpha cells, which produce the hormone glucogon, to increase glucose concentration in the blood; beta cells, which produce insulin to lower blood glucose; and delta cells, which regulate insulin and glucogen secretions. Thymus Gland - The thymus gland lies beneath the sternum (breastbone) and above the trachea (wind pipe) and heart. There are two lobes to this gland and each are made of Lymphatic tissue. It establishes the immune system from the time of gestation until puberty. After puberty it begins to shrink.Ovaries – In females, the two ovaries secrete the hormones oestrogen and progesterone which are essential to sexual development and fertility. Oestrogen is produced by an egg as it develops inside its follicle. At ovulation, when the mature egg is released, the empty follicle forms into a small tissue mass, known as the corpus luteum, which secretes progesterone. The ovaries are attached to the uterus by an anchoring ligament; the ovaries contain blood vessels, corpus luteum, which are the small tissue masses formed from an empty egg follicle to produce progesterone; and eggs, which develop inside the follicle and produce oestrogen. Testes – In males, the two testes produce sex hormones known as androgens, the most important of which is testosterone. At puberty, testosterone levels in the body rise rapidly, stimulating the production of sperm and causing the sex organs to mature. Testosterone also influences the development of male secondary sexual characteristics, such as facial hair and deepening of the voice. The testes are made up of the Vas deferens, which is the tube that transports sperm to the urethra; the Epididymis which is where developing sperm is stored to mature and the Seminiferous tubule, where sperm are produced inside coiled tubules. 12a – Explain the anatomical and physiological differences between men and women. Aside from the genital differences between men and women, there are several other differences including: * The female thoracic cage is generally more rounded than and not as big as in the male. * The female pelvis is adapted for gestation: it is not as high and is proportionately wider than that of the male. * The sacrum of the female is wider and the pelvic ring is wider and more circular to facilitate the passage of the newborn. * Greater hip width in women influences the position of the femurs, which are often more angled than in men * An average man is taller and heavier than an average woman. * The lumbar curve tends to be more exaggerated in women. * Men have more bodily hair than women do, especially on the chest and extremities * On average, girls begin puberty changing approximately two years before boys. * Men have larger hearts and lungs, and their higher levels of testosterone cause them to produce greater amounts of red blood cells. * Differences in intake and delivery of oxygen translates into some aspects of performance: when a man is jogging at about 50% of his capacity, a woman will need to work at over 70% of her capacity to keep up with him. * Female fertility decreases after age 35, ending with menopause, but men are capable of making children even when very old. * Men’s skin has more collagen and sebum, which makes it thicker and oilier than women’s skin. * Women generally have a greater body fat percentage than men. * Men and women have different levels of certain hormones; for example, men have a higher concentration of androgens such as testosterone, while women have a higher concentration of estrogens. * An average male brain has approximately 4% more cells and 100 grams more brain tissue than an average female brain. This is not connected with intelligence! Research points to no overall difference in intelligence between males and females. However, both sexes have similar brain weight to body weight ratios. * Women tend to be more flexible than men , but not as strong. * The cardio vascular system (blood circulation system) of men and women on average differ as follows: * Men has ± 40% more blood volume in the body then women * Men has ± 80% larger heart then women * Men has ± 11% more red blood cells in the body then women * Men has ± 11% more haemoglobin in the body then womenThe cardio respiratory system (oxygen carrying system) of men is on average ± 39% bigger than the cardio respiratory system of women and the consumption of oxygen of women is 17% less than men. There are however virtually no difference in the anaerobic capacity (energy production without oxygen) of men and women.12b – Explain the performance differences between men and women Females in general have a lower maximum aerobic power capacity than men (65-75% of male aerobic power) due to lower haemoglobin levels and a greater amount of adipose tissue (fat). They also play at an exercise intensity of around 70% of VO2 Max.A typical man has about twice as much muscle and half as much fat as a similarly sized woman and therefore men are stronger than women.
Women are about 7% more flexible in their limbs and joints than men. Men have longer bones with greater density while women have a lower center of gravity. A women's weight is more centered around the hips and thighs, and all of this allows for greater mobility in most women's joints when compared to a man with similar athletic ability. This added flexibility also helps to make women more coordinated and less likely to injure themselves. |