<P> After initiation of an action potential , the refractory period is defined two ways : 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 , de-inactivate , and regain their ability to open in response to stimulus . </P>
<P> After initiation of an action potential , the refractory period is defined two ways : 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 , de-inactivate , and regain their ability to open in response to stimulus . </P>
the stage in action potential that immediately follows depolarization is known as
the stage in action potential that immediately follows depolarization is known as
the refractory period
the refractory period