試題詳解

55. The action potential depolarizes the cell membrane and transiently bring the membrane potential above 0 mV, then rapidly repolarizes with an undershoot, yet the membrane potential eventually returns to the resting membrane potential at ~ -70 mV. Which ion channel mediates the rapid repolarization?
(A) Ca²⁺ channel
(B)Na⁺channel
(C) K⁺channel
(D) ATP diannel
(E) All of the above