Which part of the heart is known as the pacemaker?

The sinoatrial node, often referred to as the SA node, is known as the heart's natural pacemaker. It is located in the right atrium and is responsible for initiating the electrical impulses that trigger each heartbeat. The SA node generates electrical signals at a regular rhythm, which then spread throughout the atria, causing them to contract and pump blood into the ventricles. This rhythmic activity sets the pace for the entire heart and is crucial for maintaining a coordinated heartbeat.

In addition to its role as the primary pacemaker, the SA node coordinates with other parts of the heart's electrical conduction system, such as the atrioventricular node and the Bundle of His, though these structures play different roles in conducting and regulating the heartbeat. The correct understanding of the SA node's function is essential for comprehending cardiac physiology and the overall electrical activity of the heart.