Point 8 Intro Pathway Deficit Note Overview Problems Contents Anatomy

Axons arising from cells within the dorsal motor X give rise to PREGANGLIONIC PARASYMPATHETIC fibers that course ventral and lateral from the nucleus to exit the brain stem dorsal and lateral to the inferior olive. These axons comprise the visceromotor component of the vagus nerve (C.N. X). Preganglionic parasympathetic fibers from the vagus wander all over the place, but eventually terminate in ganglia that contain postganglionic neurons. These terminal ganglia (NOT the sympathetic chain!) are located close to, or within the structures innervated by the short postganglionic fibers (do you remember Auerbach's plexus [myenteric] and Meissner's plexus [submucosal] within the gut?). Preganglionic parasympathetic visceromotor fibers from the vagus activate postganglionic neurons in ganglia associated with the pharynx, larynx and esophagus. Short postganglionic parasympathetic fibers in turn innervate GLANDS and SMOOTH MUSCLE in these structures.