Why are action potentials usually conducted in one direction?
A) Ions can flow along the axon in only one direction.
B) Voltage-gated Na+ channels are inactivated during the refractory period.
C) The axon hillock has a higher membrane potential than the terminals of the axon.
D) Voltage-gated channels for both Na+ and K+ open in only one direction.

Question

Quizplus · Accepted Answer

During an action potential, voltage-gated Na+ channels open and allow Na+ to enter the cell, causing depolarization. However, these channels then become inactivated during the refractory period, preventing them from opening again immediately. This ensures that the action potential can only travel in one direction, towards the terminals of the axon. If the Na+ channels were not inactivated, the action potential could potentially travel in both directions along the axon.

Why Are Action Potentials Usually Conducted in One Direction