The relative refractory period occurs after the action potential is complete because of the A) lingering inactivation of the voltage-gated Na⁺ channels B) slowness of the voltage-gated K⁺ channels C) action of the sodium-potassium pumps D) lingering inactivation of the voltage-gated Na⁺ channels and slowness of the voltage-gated K⁺ channels E) slowness of the voltage-gated K⁺ channels and action of the sodium-potassium pumps

Question

Quizplus · Accepted Answer

The relative refractory period occurs because of both the lingering inactivation of the voltage-gated Na⁺ channels and the slowness of the voltage-gated K⁺ channels. During the resting state, the Na⁺ channels are inactivated and cannot open, making it difficult to produce an action potential. After the action potential, some of these channels remain inactivated for a period of time, contributing to the relative refractory period. Additionally, the voltage-gated K⁺ channels that repolarize the membrane potential during the action potential also take some time to reset before they can be activated again, contributing to the relative refractory period.

The Relative Refractory Period Occurs After the Action Potential Is