Unformatted text preview: + and K + close and there is opening of voltage-gated Ca 2+ channels that lead to influx of Ca 2+ and further depolarization. Phase 3: At the peak of the action potential, the Ca 2+ channels close and K + channels open. Phase 4: The repolarization is due to an efflux of K + . At -60mV, the K + channels are closed....
View Full Document
- Fall '09
- The Canon of Medicine, K+ channels, Cardiovascular Physiology