Autonomic nervous system (A.N.S.) is a peripheral complex of nerves, plexuses and ganglia that are organized to modulate the involuntary activity of the secretory glands, smooth muscles and visceral organs. This system functions to sustain homeostatic conditions during periods of reduced physical and emotional activity, and equally important, to assist in internal bodily reactions to stressful circumstances
The autonomic nervous system is a coordinated motor system that consists of innervated cardiac muscle, smooth muscle, and glands. The ANS maintains homeostasis and provides a coordinated response to external stimulation. Much of homeostasis occurs involuntarily, but some autonomic processes have a degree of voluntary control (urination, sexual activity). The major components are the sympathetic and parasympathetic nervous systems.