What term describes cardiac action potentials that have a rapid depolarization and repolarization with no refractory period?

The term that describes cardiac action potentials characterized by rapid depolarization and repolarization without a refractory period is autorhythmic. Autorhythmic cells, such as those found in the sinoatrial node, are responsible for initiating the electrical impulses that regulate the heartbeat. These cells can generate action potentials spontaneously, leading to rhythmic contractions of the heart.

In autorhythmic action potentials, there is a unique property where the cells can rapidly change their membrane potential, allowing for quick cycles of depolarization and repolarization. The absence of a refractory period contrasts with contractile cardiac action potentials, which do have a refractory period that prevents immediate re-excitation. The synchronous action of cardiac tissues is essential for efficient heart function, but it does not specifically denote the rapid depolarization and repolarization characteristics alone.

Understanding this concept is crucial for grasping the mechanisms behind cardiac rhythms and how various cardiac cell types function in the coordination of heartbeats.