During the rising (depolarizing) phase of a neuronal action potential, A) P_K+ becomes much greater than P_Na+. B) P_Na+ becomes much greater than P_K+. C) P_K+ is the same as P_Na+. D) Na⁺ efflux (flow out of the cell) occurs. E) K⁺ flows rapidly into the cell.

Question

Quizplus · Accepted Answer

During the rising (depolarizing) phase of a neuronal action potential, the membrane potential becomes more positive due to an influx of positively charged sodium ions into the cell. As a result, the permeability of the membrane to sodium ions (P_Na+.) becomes much greater than the permeability to potassium ions (P_K+.).

During the Rising (Depolarizing) Phase of a Neuronal Action Potential