What structure in the heart is responsible for regulating heart rate?

The sinoatrial (SA) node is referred to as the heart's natural pacemaker, and it plays a crucial role in regulating heart rate. Located in the right atrium, the SA node generates electrical impulses that initiate and coordinate each heartbeat. When the SA node fires, it sends out signals that cause the atria to contract and push blood into the ventricles. This process establishes the rhythm for the entire heart, determining how fast or slow the heart beats based on the body's needs. Therefore, the SA node is essential for maintaining a steady and appropriate heart rate in response to various physiological demands, like exercise or rest.