The prolonged electrical depolarization of cardiac muscle cells that occurs during contraction is due primarily to the persistent influx of what ion?
A)Sodium
B)Calcium
C)Nitrate
D)Chloride
E)Potassium

Question

Quizplus · Accepted Answer

The prolonged electrical depolarization of cardiac muscle cells during contraction is due primarily to the persistent influx of calcium ions through voltage-gated calcium channels. This calcium influx triggers the release of more calcium from the sarcoplasmic reticulum, leading to contraction of the cardiac muscle cells. While sodium ions also play a role in the initial depolarization of the cardiac muscle cells, they are rapidly pumped out of the cell, whereas calcium ions continue to enter the cell and contribute to the sustained depolarization.

The Prolonged Electrical Depolarization of Cardiac Muscle Cells That Occurs