The
parasympathetic nervous system (usually abbreviated
PSNS, not PNS, to avoid confusion with the
peripheral nervous system [PNS]) is one of the two divisions of the
autonomic nervous system, the other being the
sympathetic nervous system. The autonomic nervous system is responsible for regulating the body's unconscious actions. The parasympathetic system is responsible for stimulation of "rest-and-digest" or "feed and breed" activities that occur when the body is at rest, especially after eating, including
sexual arousal,
salivation,
lacrimation (tears),
urination,
digestion and
defecation. Its action is described as being complementary to that of the
sympathetic nervous system, which is responsible for stimulating activities associated with the
fight-or-flight response.