How do myelin sheaths increase the speed with which action potentials are propagated along an axon?
A)They increase the permeability of Na⁺ ions in the plasma membrane.
B)They amplify the action potential by increasing sodium influx along the entire distance of the neuron.
C)They cause action potentials to "jump" down the axon rather than travel in a continuous path along every site on the axon.
D)All of the above answers apply.

Question

Quizplus · Accepted Answer

Myelin sheaths cause action potentials to "jump" down the axon rather than travel in a continuous path along every site on the axon, a process known as saltatory conduction. This allows the action potential to travel faster along the axon, as it only needs to depolarize the nodes of Ranvier where the myelin is not present, rather than every single ion channel on the axon. This greatly increases the speed at which the action potential travels.

How Do Myelin Sheaths Increase the Speed with Which Action