Which division of the autonomic nervous system calms the body and conserves energy?

The parasympathetic nervous system is responsible for calming the body and conserving energy. This division of the autonomic nervous system works to promote a "rest and digest" state, which occurs during periods of relaxation or after eating. It slows down the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract. By doing so, it facilitates bodily functions that are essential for recovery and replenishment of energy.

This system functions by releasing neurotransmitters, primarily acetylcholine, that help to initiate the processes of digestion and other restorative functions without the stress response elicited by the sympathetic nervous system. The focus is on energy conservation and maintaining homeostasis, emphasizing the body's recovery after periods of stress or activity.