Phase 0 of the cardiac muscle cell action potential is associated with ________ channels.
A) opening of slow calcium ion
B) opening of fast potassium ion
C) opening of fast sodium ion
D) closure of sodium leak

Question

Quizplus · Accepted Answer

Phase 0 begins when the membrane potential approaches threshold and voltage-gated "fast" sodium channels open momentarily.Calcium enters the cell during Phase 2.Potassium enters the cell during phase 1.Phase 0 of the cardiac muscle cell action is not associated with the closure of the slow sodium leak.

Phase 0 of the Cardiac Muscle Cell Action Potential Is