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

In myelinated axons, voltage-gated Na⁺ and K⁺ channels are concentrated at the nodes of Ranvier, which are the unmyelinated segments. This concentration facilitates saltatory conduction, allowing the action potential to "jump" from node to node, increasing the speed of propagation.

What Axonal Characteristic Facilitates the Propagation of an Action Potential