The structure that keeps the heart functioning is called the cardiac conduction system. This system consists of specialized cardiac muscle cells that generate and propagate electrical impulses necessary for heart contractions. Key components include the sinoatrial (SA) node, which acts as the heart's natural pacemaker, the atrioventricular (AV) node, and the bundle of His, along with Purkinje fibers. These structures ensure synchronized contractions of the atria and ventricles, enabling efficient blood circulation throughout the body. Any disruptions in this system can lead to arrhythmias or other heart-related issues, underscoring its vital role in cardiovascular health.