branches (anatomy)

Last reviewed 01/2018

The vagus nerve originates from vagal nuclei within the medulla. A series of rootlets from these nuclei emerge on each side of the ventral medulla in the cleft between the pons and inferior cerebellar peduncle; at this point they are inferior to the glossopharyngeal nerve rootlets and superior to the accessory nerve rootlets. The rootlets then merge into one nerve on each side as they pass anterolaterally with both glossopharyngeal nerve (superiorly) and accessory nerve (inferiorly). Each vagal nerve then passes through the central portion of the jugular foramen and in tandem, through the arachnoid and dura mater, with the accessory nerve sited laterally.

At the level of the inferior margin of the jugular foramen on each side, each vagus nerve forms a superior and then an inferior ganglion. At the inferior ganglion it receives special visceral motor fibres from the accessory nerve. At the level of each superior ganglion, two small cervical branches are given off. At the level of the inferior ganglion, the following branches are given off:

• pharyngeal nerve
• superior cardiac nerve
• superior laryngeal nerve

Each vagus nerve then descends within the carotid sheath posteriorly and intermediate between the internal jugular vein and the internal carotid artery superiorly, or the common carotid artery inferiorly. The right and left vagi then take different routes within the thorax. Both form a recurrent laryngeal nerve and branches to the plexuses of the heart, oesophagus and bronchial tree before traversing the diaphragm as the vagal trunks to supply the abdominal viscera. These are considered further in the submenu.