In Figure 37.1, the minimum graded depolarization needed to operate the voltage-gated sodium and potassium channels is indicated by the label
A) A.
B) B.
C) C.
D) D.
E) E.

Question

Quizplus · Accepted Answer

The minimum graded depolarization needed to operate the voltage-gated sodium and potassium channels is indicated by the label A. This is because the threshold potential for the voltage-gated sodium channels is lower than that for the voltage-gated potassium channels, so the sodium channels will open first and allow sodium ions to flow into the cell, causing the membrane potential to depolarize. This depolarization will then open the voltage-gated potassium channels, allowing potassium ions to flow out of the cell and repolarize the membrane.