dorsal nucleus of vagus nerve dorsal nucleus of vagus nerve the dorsal nucleus of vagus nerve (or posterior nucleus of vagus nerve or dorsal vagal nucleus or nucleus dorsalis nervi vagi or nucleus posterior nervi vagi) is a cranial nerve nucleus for the vagus nerve in the medulla that lies ventral to the floor of the fourth ventricle. it mostly serves parasympathetic vagal functions in the gastrointestinal tract, lungs, and other thoracic and abdominal vagal innervations. these functions include, among others, bronchoconstriction and gland secretion. the cell bodies for the preganglionic parasympathetic vagal neurons that innervate the heart reside in the nucleus ambiguus. dorsal nucleus of vagus nervenuclei of origin of cranial motor nerves schematically represented; lateral view. ("x" visible at bottom center.)#9 is vagus nerve and nucleusdetailsidentifierslatinnucleus posterior nervi vagi, nucleus dorsalis nervi vagineuronames755neurolex idbirnlex_2642ta98a14.1.04.229ta26013fma54585anatomical terms of neuroanatomy additional cell bodies are found in the nucleus ambiguus, which give rise to the branchial efferent motor fibers of the vagus nerve (cn x) terminating in the laryngeal, pharyngeal muscles, and musculus uvulae. additional images section of the medulla oblongata at about the middle of the olive. the cranial nerve nuclei schematically represented; dorsal view. motor nuclei in red; sensory in blue. dorsal motor nucleus of vagus with lewy body pathology