In response to a stimulus, Na⁺ and K⁺ channels open, allowing for depolarization. The channels respond independently, with
A)both Na⁺ and K⁺ channels opening simultaneously and both remaining active until the end of the action potential.
B)the K⁺ channel opening first, then the Na⁺ channel opening, and only the Na⁺ channel remaining active until the end of the action potential.
C)the Na⁺ channel opening first, then K⁺ channel opening and only the K⁺ channel remaining active until the end of the action potential.
D)both Na⁺ and K⁺ channels opening simultaneously, with the K⁺ channel closing before the Na⁺ channel.
E)the Na⁺ channel opening first, then the K⁺ channel opening, and both remaining active until the end of the action potential.

Question

Quizplus · Accepted Answer

The Na+ channel opens first, allowing Na+ to enter the cell and depolarize it. This depolarization causes the K+ channel to open, allowing K+ to leave the cell and repolarize it. The K+ channel remains active until the end of the action potential, while the Na+ channel closes after a short period of time.

In Response to a Stimulus, Na⁺ and K⁺ Channels Open