NERVOUS SYSTEM SPECIAL SENSE
CEREBELLUM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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an action potential occurs at a neurolemmocyte
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an action potential occurs at each of node of Ranvier
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only continuous conduction can occur
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the threshold is lower than in unmyelinated neurons
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Detailed explanation-1: -The Nodes of Ranvier are only present when the axon of a neuron is myelinated. Myelination allows for an increased rate of action potential transmission due to action potentials “jumping” between Node of Ranvier, this is called saltatory conduction .
Detailed explanation-2: -The action potential propagated by one node of Ranvier jumps to and is regenerated at the next node along the axon, thereby enabling the action potential to travel rapidly along the fibre.
Detailed explanation-3: -Due to the presence of the insulating myelin sheath at internodes and voltage-gated sodium channels at nodes, the action potential in myelinated nerve fibers jumps from one node to the next.
Detailed explanation-4: -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.