PHYSIOLOGY
CENTRAL NERVOUS SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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help speed up impulse
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help slow down impulse
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protecting the axon
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insulating the axon
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Detailed explanation-1: -[2] The nodes contain high concentrations of voltage-gated sodium ion channels, responsible for raising membrane voltage during the creation of an all-or-nothing action potential.
Detailed explanation-2: -In myelinated axons, the nodes of Ranvier function as repeaters to regenerate the action potential as it propagates in a saltatory manner along the axon to the nerve terminal, thereby dramatically increasing the speed of action potential propagation4, 5.
Detailed explanation-3: -Because the myelin sheath is largely composed of an insulating fatty substance, the nodes of Ranvier allow the generation of a fast electrical impulse along the axon. This rapid rate of conduction is called saltatory conduction.
Detailed explanation-4: -node of Ranvier, periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses.