The depolarization phase of an action potential requires ________.
A) opening of K+ channels in the membrane
B) opening of Na+ channels in the membrane
C) opening of Ca2+ channels in the membrane
D) a K+ concentration gradient across the membrane
E) a Ca2+ concentration gradient across the membrane

Question

Quizplus · Accepted Answer

During the depolarization phase of an action potential, Na+ channels in the membrane open, allowing Na+ ions to enter the cell and causing the membrane potential to become more positive.

The Depolarization Phase of an Action Potential Requires ________