Control of the heart rate

The heart rate is controlled by the autonomic nervous system, which automatically adjusts heartbeats based on the body’s needs. When you're active or stressed, signals from the sympathetic nervous system increase heart rate to supply more oxygen-rich blood. During rest or relaxation, the parasympathetic nervous system slows the heart rate to conserve energy. The heart's natural pacemaker, called the sinoatrial (SA) node, generates electrical signals that set the pace. These signals are influenced by chemical messengers like adrenaline and the body’s overall condition, ensuring the heart beats appropriately whether you're resting, exercising, or in danger.