parasympathetic

Definition of parasympathetic nervous system

parasympathetic nervous system

(PAYR-uh-SIM-puh-THEH-tik NER-vus SIS-tem)
The part of the nervous system that slows the heart, dilates blood vessels, decreases pupil size, increases digestive juices, and relaxes muscles in the gastrointestinal tract.

Source: NCI Dictionary of Cancer Terms