The autonomic nervous system regulates involuntary and unconscious actions, such as internal-organ function, breathing, digestion, and heartbeat. ... The parasympathetic nervous system activates a “rest and digest” or “feed and breed” response after these stressful events, which conserves energy and replenishes the system.
Heart rate is controlled by the two branches of the autonomic (involuntary) nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The sympathetic nervous system (SNS) releases the hormones (catecholamines - epinephrine and norepinephrine) to accelerate the heart rate.
B. Autonomic
Sorry for not answering soon I didnt see your question. Hope it helps though :)
