The heart operates through a remarkable cycle driven by specialized cells at the sinoatrial node, which generate action potentials that propagate through the heart. This process involves a three-stage mechanism: depolarization at the sinoatrial node, activation of the atrioventricular node, and contraction of the ventricles via Purkinje fibers. The heart's ability to maintain this rhythm continuously for decades is a testament to its incredible design and functionality.
