During the rising (depolarizing)phase of an action potential, A)PK⁺ becomes much greater than PNa⁺ B)PNa⁺ becomes much greater than PK⁺ C)PK⁺ is the same as PNa⁺ D)Na⁺ efflux (flow out of the cell) occurs E)None of the choices occur

Question

Quizplus · Accepted Answer

During the rising (depolarizing) phase of an action potential, PNa⁺ becomes much greater than PK⁺. This is because the opening of voltage-gated Na+ channels allows a rapid influx of Na+ ions into the cell, which results in membrane depolarization and leads to the generation of an action potential. During this phase, the PK channels are mostly closed and do not contribute significantly to the membrane potential.

During the Rising (Depolarizing)phase of an Action Potential