Definition of System, parasympathetic nervous

System, parasympathetic nervous: A part of nervous system that slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles. The parasympathetic nervous system together with the sympathetic nervous system (that accelerates the heart rate, constricts blood vessels, and raises blood pressure) constitute the autonomic nervous system.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=5691
Last Editorial Review: 6/14/2012