AAET NCV/EMG Questions & Answers

AAET NCV/EMG Questions & Answers Ion What describes an atom in which the total number of electrons is not equal to the total number of protons, giving the atom a net positive or negative electrical charge? Electron What is the negatively charged particle in an atom? Neutrons What has neutral particles, along with protons, and is found in the nucleus of an atom? Protons Which particles of an atom are positively charged? Atoms What makes up the elements found in all matter? -90 to -70mV What is the voltage inside the nerve cell membrane in a resting membrane potential? Sodium What is the major ion outside a cell membrane? Potassium What is the major ion inside a cell membrane? All Or None Response What is the physiological term when depolarization occurs it causes a muscle and/or nerve fiber to either respond to a stimulus completely if it reaches threshold or no response if the depolarization is insufficient to reach threshold? Depolarization What describes changing from a resting potential or polarized state to an excited state? Depolarization What causes the inside of the cell to be more positively charged relative to its resting state? Repolarization What describes when nerve cells are changed from an excited state back to a resting electrical potential or polarized state? Hyperpolarization What causes the inside of the cell to be more negatively charged relative to its resting state? Absolute Refractory Period During the repolarization phase, sodium channels become inactivated and cannot be opened no matter how much depolarization occurs and no action potential can be generated no matter how strong the stimulus. What is this? Relative Refractory Period In the later stages of repolarization, a brief increase in the permeability to potassium occurs and this results in hyperpolarizing the membrane and returning it slowly to its resting value during which time an increasing number of sodium channels can be opened. If you give a strong stimulus, it might be possible for another action potential to occur. This time is known as the? Saltatory Conduction Propagation of action potentials along myelinated axons from one Node of Ranvier to the next Node of Ranvier is called? Schawnn Cells What is the name of the cells that are surrounding the axon to form the myelin sheath? Nodes of Ranvier What describes the periodic gaps in the insulating sheath (myelin) on the axon through which ion channels allow the flow of ions across the nerve membrane? Internodal Length The length between two nodes of Ranvier is called? Sodium-Potassium Pump Forcing sodium out of the cell and potassium in is the function of what? Diameter of the axon and degree of myelination What can increase or decrease the conduction velocity of a nerve? Unmyelinated Fibers What types of fibers mediate pain, temperature, and autonomic function? Fascicles Nerve fiber bundles' having a common destination describes? Perineurium Each individual fascicle is surrounded by connective tissue called? Endoneurium What is the connective tissue between individual axons called? Epineurium What is the name of the outer supportive layer of connective tissue which surrounds the whole nerve and binds fascicles to each other? Type- A fibers are myelinated fibers of somatic nerve that can innervate muscle or skin Type B- fibers are myelinated preganglionic fibers What types of nerve fibers are myelinated? Type C - because it is unmyelinated Which type of nerve fiber is not fast and why? Type B -These fibers are myelinated but not as heavily as type A Which nerve fiber is fast but not as fast as nerve fiber type A? Axons What is the communication link between the central and peripheral nervous system? Increased diameter and myelination of nerve fibers What factors are important for fast conduction velocity? Outside of the spinal cord Where is the dorsal root ganglion located? Gray matter of anterior horn in the spinal cord Where are motor neurons located? Myofibrils What is composed of sarcomeres and is responsible for muscle contraction? Sarcomere A structural subunit and that contains actin and myosin filaments? I band Which band contains only actin filaments? H band Which band contains only myosin filaments? A band Which band contains both actin and myosin filaments? At the end of each sarcomere Where are the Z bands located? Type I- slow twitch, or "red" muscle, is dense with capillaries and is rich in mitochondria and myoglobin, giving the muscle tissue its characteristic red color. Slow twitch fibers contract for long periods of time but with little force. What muscle fiber is called slow twitch muscle fiber? Type II a and Type II b Fast twitch fibers contract quickly and powerfully but fatigue very rapidly, sustaining only short, anaerobic bursts of activity before muscle contraction becomes painful. They contribute most to muscle strength and have greater potential for increase in mass. Type II b muscle fiber is white in color. Which muscle fiber is called fast-twitch muscle fiber? Thick Myosin What filament is contained in the center of sarcomere? Thin Actin Which filament is extending from either side of the Z line? Calcium What is released from the sarcoplasmic reticulum that aids in muscle contraction? To store calcium ions (Ca 2 +) What is the primary function of Sarcoplasmic Reticulum? Dorsal Scapular and Long Thoracic Nerves Which two nerves originate directly from the cervical spinal nerve roots? Mixed spinal nerve Motor and sensory roots at each spinal level unite distal to the dorsal root ganglia to become? C5-T1 What nerve roots contribute to the organization of the brachial plexus?? Five roots C5-T1 Three trunks - upper, middle and lower Two divisions of each trunk Three cords Terminal nerves What are the five components of the brachial plexus? Anterior rami ofC5-C6 roots What nerve roots make up the upper trunk? C7 Which nerve root supplies the middle trunk?