What causes the refractory period of a neuron?
A) Excessive sodium flows out of the neuron after it fires.
B) Excessive sodium enters the neuron after it fires.
C) Excessive potassium enters the neuron after it fires.
D) Excessive potassium flows out of the neuron after it fires.

Question

Quizplus · Accepted Answer

During the firing of a neuron, depolarization causes potassium ions to exit the neuron and sodium ions to enter. This results in the nerve cell interior becoming more positively charged, leading to an action potential or nerve impulse. After firing, the potassium channels remain open and excessive potassium continues to exit the neuron, causing the refractory period. During the refractory period, the neuron cannot be restimulated because the neuron must first restore the ion concentration gradients before it can fire again.

What Causes the Refractory Period of a Neuron