Which component regulates the electrical impulses in the heart?

The SA node, or sinoatrial node, is often referred to as the natural pacemaker of the heart. It is located in the right atrium and plays a crucial role in regulating the heart's electrical impulses. The SA node generates electrical signals that initiate each heartbeat, determining the heart rate and rhythm. This electrical activity spreads through the atria, causing them to contract and push blood into the ventricles.

While other components, such as the AV node, Bundle of His, and Purkinje fibers, also play essential roles in the conduction system of the heart, their functions are more about relaying and coordinating the impulses rather than initiating them. The AV node serves to delay the signal from the atria before it passes to the ventricles, the Bundle of His conducts impulses to the ventricles, and Purkinje fibers distribute the electrical signal throughout the ventricular myocardium. However, the SA node is the primary component that starts and regulates the electrical impulses, making it the most critical element in determining the heart's overall rhythm.