What is the first event of an action potential?
A)Voltage-gated sodium channels open.
B)Sodium ions leave the cell.
C)Voltage-gated potassium channels open.
D)Potassium ions leave the cell.
E)Both voltage-gated sodium and potassium channels open.

Question

Quizplus · Accepted Answer

The first event of an action potential is the opening of voltage-gated sodium channels, allowing the influx of sodium ions into the cell. This depolarizes the membrane potential and triggers the rest of the action potential sequence. Option B, C, and D describe events that occur after the initial depolarization. Option E is incorrect because both channels don't open at the same time; sodium channels open first, and potassium channels open slightly later.

What Is the First Event of an Action Potential