What mechanism explains the absolute refractory period in excitable neuronal membranes?
Answer and explanation
Correct answer: D. Inactivation of voltage-gated sodium channels by intracellular inactivation gates
During the absolute refractory period, voltage-gated Na+ channels are inactivated (inactivation gate closed) and cannot be reopened by any stimulus until the membrane repolarizes and the channels reset to their closed resting state.
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