-In what stage(s) is(are) voltage-gated sodium channels opening?
A) stage 2 only
B) stage 3 only
C) stages 2 and 3
D) stages 3 and 4
E) stages 2, 3, and 4

Question

-In what stage(s) is(are) voltage-gated sodium channels opening?
A) stage 2 only 
B) stage 3 only 
C) stages 2 and 3 
D) stages 3 and 4 
E) stages 2, 3, and 4

Quizplus · Accepted Answer

Voltage-gated sodium channels are opening during stages 2 and 3. In stage 2, the membrane potential reaches threshold and voltage-gated sodium channels begin to open. In stage 3, more voltage-gated sodium channels open and there is a rapid influx of sodium ions into the cell. Therefore, the best choice is C which includes both stages 2 and 3.

-In What Stage(s) Is(are) Voltage-Gated Sodium Channels Opening