Vagus Nerve

Overview

"Vagus" is from the Latin meaning wandering. This is a fitting name as the nerve wanders from the brainstem to the splenic flexure of the colon. The vagus nerve consists of five components with distinct functions:

Branchial motor
(special visceral efferent)
Supplies the voluntary muscles of the pharynx and most of the larynx, as well as one extrinsic muscle of the tongue.
Visceral motor
(general visceral efferent)
Parasympathetic innervation of the smooth muscle and glands of the pharynx, larynx, and viscera of the thorax and abdomen.
Visceral sensory
(general visceral afferent)
Provides visceral sensory information from the larynx, esophagus, trachea, and abdominal and thoracic viscera, as well as the stretch receptors of the aortic arch and chemoreceptors of the aortic bodies.
General sensory
(general somatic afferent)
Provides general sensory information from the skin of the back of the ear and external auditory meatus, parts of the external surface of the tympanic membrane, and the pharynx.
Special sensory
(special afferent)
A very minor component of CN X. Provides taste sensation from the epiglottic region. This component will not be discussed further.