CN X - Vagus nerve

CN X, the vagus n. is the main route of pre-ganglionic parasympathetic neurons.  The vagus n. emerges from the pontomedullary junction and passes through the jugular foramen into the neck.  It gives off a superior branch to the larynx, passes through the carotid sheath, and enters the thorax.  It gives off recurrent branches to the larynx, then provides innervation to the heart and lungs, before passing through the esophageal hiatus and providing parasympathetic innervation to much of the abdominal viscera (foregut, midgut, adrenal glands and kidneys).  It’s estimated that 80% to 90% of the nerve fibers in the vagus n. are sensory, and provide information about the state of the viscera the nerve innervates.  The vagus n. is also motor to skeletal muscles (specifically branchial muscles) of the larynx and pharynx.