Question

Which one of the following can cause the interior of the neuron to have a momentary positive charge?

(a) Opening of potassium leak channels
(b) Activity of the Na/K ATPase
(c) Opening of voltage gated sodium channels
(d) Opening of voltage gated potassium channels

Answer 1

(c) Opening of voltage gated sodium channels

Step-by-step explanation:

The firing of action potential leads to a quick opening of voltage-gated Na+ channels and slow opening of K+ channels. The opened voltage-gated Na+ channels allow the Na+ to enter the neuron and cause depolarization.

The interior of the cell becomes positive quickly. As the rising potential passes 0 mV, the voltage-gated Na+ channels are inactivated and the entry of the Na+ stops while the K+ channels are fully opened to repolarize the membrane again.