An action potential occurs when:
A) sodium ions enter the axon's interior, causing a brief positive electrical impulse.
B) potassium ions are electrically transformed into sodium ions.
C) polarized dendrites stimulate adjoining nodes of Ranvier.
D) potassium ions enter the dendrites and sodium ions exit the axon, causing depolarization and a brief negative electrical charge.

Question

Quizplus · Accepted Answer

An action potential occurs when sodium ions enter the axon's interior, causing a brief positive electrical impulse. This is known as depolarization, and it triggers the opening of voltage-gated ion channels along the axon membrane. The influx of sodium ions causes the interior of the axon to become more positive, which propagates the electrical impulse down the length of the axon.

An Action Potential Occurs When