the parasympathetic nervous system exits the central nervous system at cranial nerves III, VII, IX and X and the sacral spinal roots. Nerve fibers from the central nervous system to the ganglion are preganglionic fibers and use acetylcholine as a neurotransmitter. The parasympathetic nervous system innervates visceral organs and glands. The parasympathetic nervous system slows the heart rate, stimulates digestion and relaxes sphincters.
