Question

The action potential always moves in one direction because of _____.

• A. Closing of the voltage regulated gate of the Voltage gated Sodium channels
• B. Sodium potassium ATPase pump
• C. Closing of the inactivation gate of Voltage gated Sodium channels
• D. Synaptic neurotransmitter release

Answer 1

The correct option is C

Closing of the inactivation gate of Voltage gated Sodium channels

Closing of the inactivation gate of voltage gated Sodium channels. This gate of the voltage gated Sodium channel is not regulated, it closes a while after the channel is open and reopens again after a small period. The period when this gate is closed is known as the refractory period, as the channel does not respond to voltage changes during this period. The activity of this gate also ensures that the action potential moves in the forward direction. The voltage gate opens when the signal reaches the site, and inactivation gate closes the channels as the signal passes.