The parasympathetic nervous system is a subdivision of the autonomic nervous system (ANS), which regulates bodily functions outside of voluntary control, therefore being automatic. It is also called the ‘rest and digest' system as it conserves the body’s natural activity and relaxes the individual once an emergency has passed. It promotes relaxation, energy conservation, and recovery by slowing the heart rate, stimulating digestion, and facilitating other processes when the body is resting. It counterbalances the sympathetic nervous system, which governs "fight or flight" responses.
