[TA] a mixed nerve that arises by numerous small roots from the side of the medulla oblongata through the retroolivary groove, between the glossopharyngeal above and the accessory below; it leaves the cranial cavity by the jugular foramen and passes down to supply the pharynx, larynx, trachea, lungs, heart, and gastrointestinal tract as far as the left colic (splenic) flexure. SYN: nervus vagus [CN X] [TA], pneumogastric nerve, tenth cranial nerve [CN X], vagus.