How would the absolute refractory period be affected if voltage-regulated sodium channels failed to become inactivated?...

How would the absolute refractory period be affected if voltage-regulated sodium channels failed to become inactivated?

A. it would be longer

B. it would be shorter

C. it would be the same

Solutions

Expert Solution

How would the absolute refractory period be affected if voltage-regulated sodium channels failed to become inactivated?

Answer is A. it would be longer

Absolute refractory period is the period from the initiation of the action potential to immediately after the peak is referred.

The absolute refractory period coincides with nearly the entire duration of the action potential. In neurons, it is caused by the inactivation of the Na+ channels that originally opened to depolarize the membrane. These channels remain inactivated until the membrane hyperpolarizes. The channels then close, activate, and regain their ability to open in response to stimulus.

The refractory periods are due to the inactivation property of voltage-gated sodium channels and the lag of potassium channels in closing. Voltage-gated sodium channels have two gating mechanisms, the activation mechanism that opens the channel with depolarization and the inactivation mechanism that closes the channel with repolarization. While the sodium channel is in the inactive state, it will not open in response to depolarization. The period when the majority of sodium channels remain in the inactive state is the absolute refractory period.

Sydney Mullin answered 1 year ago

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