試題詳解

2. During the generation of an action potential, which of the following best explains the absolute refractory period at the molecular level?
(A) The K+ channels remain open, preventing the membrane from reaching the threshold potential.
(B) The Nat channels are inactivated, preventing further depolarization despite strong stimuli.
(C) The Na+/K+-ATPase pump is actively hyperpolarizing the membrane, inhibiting depolarization.
(D) The relative permeability of Nat remains high, preventing K+ efflux from dominating.
(E) The lipid bilayer of the membrane is temporarily impermeable to all ions.