The primary reason why neurons are refractory for a short period after firing action potentials, and the reason underlying the absolute refractory period, is that the
A)voltage-gated sodium channels are inactivated.
B)voltage-gated potassium channels are inactivated.
C)sodium-potassium pump has to remove sodium ions from inside the cell.
D)sodium-potassium pump has to retrieve potassium ions from outside the cell.

Question

Quizplus · Accepted Answer

During an action potential, voltage-gated sodium channels open and allow an influx of sodium ions into the cell, depolarizing the membrane. These channels then become inactivated, preventing another action potential from firing immediately. This is known as the absolute refractory period, during which no amount of stimulation can generate another action potential. The channels eventually transition back to a closed, but not inactivated, state, allowing the neuron to fire again during the relative refractory period. The inactivation of sodium channels is the primary reason for the refractory period. The sodium-potassium pump does play a role in returning the membrane potential to its resting state after an action potential, but it is not the primary reason for the refractory period.

The Primary Reason Why Neurons Are Refractory for a Short