Cardiomyocytes have a much longer repolarization period than skeletal muscles due to their
A)voltage-sensitive Na⁺ channels.
B)voltage-sensitive Ca²⁺ channels.
C)voltage-sensitive K⁺ channels.
D)voltage-sensitive Cl⁻ channels.

Question

Quizplus · Accepted Answer

Cardiomyocytes have a longer repolarization period primarily due to the action of voltage-sensitive Ca²⁺ channels. These channels allow a prolonged influx of calcium ions during the plateau phase of the cardiac action potential, which is crucial for the extended duration of the contraction necessary for effective heart function. This mechanism is distinct from skeletal muscle cells, which do not have this prolonged plateau phase.

Cardiomyocytes Have a Much Longer Repolarization Period Than Skeletal Muscles