During which of the following phases is K⁺ permeability greater than at rest?
A)During the after-hyperpolarization phase of an AP
B)During vesicular release of neurotransmitter from the presynaptic neuron
C)During the repolarizing phase of an AP
D)During the depolarizating phase of an AP
E)None of these,K⁺ permeability is greatest at rest

Question

Quizplus · Accepted Answer

During the repolarizing phase of an action potential, K⁺ channels open, leading to an efflux of K⁺ from the cell and an increase in K⁺ permeability. This aids in bringing the membrane potential back to rest after depolarization. During the after-hyperpolarization phase, K⁺ permeability remains elevated, but not higher than during repolarization. During vesicular release of neurotransmitter, K⁺ permeability is not directly affected. During depolarization, K⁺ channels are largely closed, leading to a decrease in K⁺ permeability.

During Which of the Following Phases Is K⁺ Permeability Greater