the current flow in the myelinated axon4. The myelinated axon is composed of two parts‚ the unmyelinated nodes of Ranvier and the myelinated internodes. Current is conducted through the myelinated parts of the axon through a process called saltatory conduction in which sodium ions in the nodes of Ranvier interact with the sodium ions inside the myelinated internodes and subsequently with the sodium ions in the next node of Ranvier‚ vastly speeding up the process of propagating the action potential5
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Upper motor neurons and lower motor neurons act to carry nerve impulses from the brain out to the muscles in the body. Upper motor neurons supply input to the lower motor neurons. They do this by either synapsing directly to lower motor neurons‚ or by synapsing with a local circuit neuron‚ which then synapses with a lower motor neuron. The upper motor neurons originate in the motor region of the cerebral cortex or brainstem. The neurons from the cerebral cortex are important for planning‚ initiating
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Action potential‚ impulse conduction (italics)‚ and cardiac cycle (bold) Pacemaker cells in the SA node‚ found in the wall of right atrium‚ begin as polarized‚ with Na+ on the outside of the cell (sarcolemma) and the cell at its resting potential (-80 mV in the atria‚ -90 mV in the ventricles). The atria are full or filling with blood. The SA (and technically the AV) nodal cells gradually drift towards their threshold after each repolarization and depolarize (the prepotential: spontaneous depolarization)
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Laboratory – Muscle Physiology A. MUSCLE TONUS Observations‚ Report and Conclusion: A. Define muscle tonus and give its importance * Muscle tonus refers to a state of slight muscular contraction maintained by synchronous impulses of low frequency‚ discharged by the spinal motor neurons. * Reflex in nature. * Muscle tonus is a small amount of tension in the muscle due to weak‚ involuntary contractions of its motor units. Muscle tonus is important in a sense that it governs the
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I. ANATOMY AND PHYSIOLOGY OF THE HEART I. LOCATION OF THE HEART The heart is located in the chest between the lungs behind the sternum and above the diaphragm. It is surrounded by the pericardium. Its size is about that of a fist‚ and its weight is about 250-300 g. Its center is located about 1.5 cm to the left of the midsagittal plane. Located above the heart are the great vessels: the superior and inferior vena cava‚ the pulmonary artery and vein‚ as well as the aorta. The aortic arch lies
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ANTHROPOLOGY 316: Human Anatomy & Physiology I Lab Fall 2013 Lab L05-7052 Friday 12:35-2:35 AS 11 Lecturer: Kelli H. Tamvada‚ M.A. Contact Information: KTamvada@albany.edu Office location: AS 235 Office hours: Tuesdays 3:00-5:00‚ or by appointment Required Texts: Heisler‚ R. E.‚ Hebert‚ N.‚ Chinn‚ J. Krabbenhoft‚ K. M.‚ and Malakhova‚ O. (2014) PAL 3.0 Lab Guide: practical anatomy lab. Pearson Zao‚ P.‚ Stabler‚ T.‚ Smith‚ L.‚ Lokuta‚ A.‚ Griff‚ E. (2014). PhysioEx 9.0 Laboratory
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4.4 MarkingScheme For 1mark multiple-choice questions‚ 1/3 mark will be deducted for a wrong answer. Likewise‚for 2 marks multiple-choice questions‚ 2/3 mark will be deducted for a wrong answer. However‚for the linked answer question pair‚ where each question carries 2 marks‚ 2/3 mark will bededucted for a wrong answer to the first question only. There is no negative marking for wronganswer to the second question of the linked answer question pair. If the first question in thelinked pair is wrongly
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tone‚ and position of the body. Basically it controls all functions that have to do with the skeleton. Lastly‚ there is the brainstem. The brainstem is made up of three parts; the midbrain‚ pons‚ and medulla. The midbrain and pons provide conduction pathways to and from the center in the brain. They also control reflexes for eyes and head in response to visual and auditory stimuli. The medulla oblongata‚ which is located between the pons and spinal cord‚ controls basic
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pressure. 9. Excessive sweating will result in a short - term ____ in blood volume and a/an ____ in blood pressure. 10. An in epinephrine will result in ____ vessel diameter and a/an ____ in blood pressure. 2. Cardiac Conduction System 1. The intrinsic conduction sys tem consists of _______________ ____________ cells that initiate and distribute _______________ throughout the heart. se arrows in the spaces for questions 6 through 10. 6. A in hematocrit will result in ____ blood
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anesthetic such as dental procedures and minor surgeries. Lidocaine is also used to relieve itching‚ burning and pain from skin irritation and inflammation. It works by blocking the pain signals sent by the nerve endings on the skin‚ changes signal conduction in neurons by blocking sodium channels. ~Morphine is a very potent drug that is used to relieve severe pain. It can relieve pain by silencing nerves in the spine that produce pain signals‚ morphine also has complex effects in the brain. Morphine
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