cardiac action potential

The cardiac action potential is the electrical signal that causes the heart muscle to contract and pump blood. It involves a sequence of electrical changes across heart cells: a rapid influx of sodium ions causes depolarization (charge becomes positive), then calcium ions enter, maintaining the contraction. Afterwards, potassium ions exit the cell, repolarizing the membrane (restoring negative charge). This cycle ensures a rhythmic heartbeat. The process is precisely timed to coordinate the heart's pumping action, maintaining steady blood flow throughout the body.