Term
| how do action potentials move along the axon |
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Definition
they are propagated/regenerated
-each adjacent section is depolarized and a new action potential occurs
-action potentials travel in one direction bc of the refractory state of the membrane after a depolarization |
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Term
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Definition
| the speed of propagation of action potentials- varies w diameter |
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Term
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Definition
| a sheath of insulation around the axon, formed by glial cells, which speeds conducxtion |
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Term
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Definition
| small gap in the insulating myelin sheath |
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Term
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Definition
| the axon potential travels inside the axon and jumps from node to node |
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Term
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Definition
| results when the body makes ab's that attack myelin and interfere w action potential conduction, affects oligodendrocytes |
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Definition
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Term
| process of muscle contraction |
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Definition
• It occurs by an excitation-contraction coupling mechanism.
• Depolarization of the muscle membrane by Ach release from neurons causes voltage-dependent calcium channels inside the muscles to open and release intracellularly stored Ca2+.
• Ca2+ bind to a protein of the sarcomere called troponin. This begins the contraction process. (tropomyosin is moved away)
-then myosin cross bridges attach to actin and bend, pulling actin filaments towards the center of the sarcomere, powered by ATP |
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Term
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Definition
| the group of muscle fibers innervated by a single motor neuron |
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Term
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Definition
| patterns of coordinated innervation of muscles involved in the same movements |
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