Heartbeat regulation refers to the processes that control the rate and rhythm of the heart's contractions. This regulation is primarily managed by the autonomic nervous system, which includes the sympathetic and parasympathetic branches. The sinoatrial (SA) node, located in the right atrium, acts as the heart's natural pacemaker, generating electrical impulses that initiate each heartbeat. Additionally, various factors influence heartbeat regulation, such as hormones, exercise, and stress. For instance, during physical activity, the body releases adrenaline, which increases heart rate to supply more oxygen to the muscles. Conversely, during rest, the parasympathetic nervous system can slow the heart rate down, promoting relaxation and recovery.