What axonal characteristic facilitates the propagation of an action potential along a myelinated axon?
A) Voltage-gated Na+ and K+ channels are concentrated in the myelinated axonal segments.
B) Voltage-gated Na+ and K+ channels are concentrated in the unmyelinated axonal segments.
C) Voltage-gated Na+ channels are concentrated in the myelinated axonal segments; voltage-gated K+ channels are concentrated in the unmyelinated axonal segments.
D) Voltage-gated K+ channels are concentrated in the myelinated axonal segments; voltage-gated Na+ channels are concentrated in the unmyelinated axonal segments.
E) Voltage-gated Na+ K+ channels are spread evenly throughout both myelinated and unmyelinated segments.

Question

Quizplus · Accepted Answer

Voltage-gated Na+ and K+ channels are concentrated in the nodes of Ranvier, which are the unmyelinated segments of the axon. This arrangement facilitates saltatory conduction, where action potentials jump from node to node, speeding up signal transmission along myelinated axons.

What Axonal Characteristic Facilitates the Propagation of an Action Potential