The plateau of the cardiac action potential results from the opening of voltage-gated slow ____ channels in the plasma membrane of the cardiac cell.
A) sodium
B) potassium
C) calcium
D) chloride
E) glucose

Question

Quizplus · Accepted Answer

The plateau of the cardiac action potential is due to the opening of voltage-gated slow calcium channels. These channels allow for an influx of calcium into the cell, which prolongs the depolarization phase of the action potential and thus contributes to the plateau phase. Sodium channels contribute to the initial depolarization phase of the action potential, while potassium channels contribute to the repolarization phase. Chloride channels are important for regulating ion balance across the cell membrane but do not contribute to the cardiac action potential. Glucose channels do not exist.

The Plateau of the Cardiac Action Potential Results from the Opening