Quick Facts
Origin: Inferior ganglion of vagus nerve.
Course: Runs inferiorly, posterior to the internal carotid artery, and on the lateral surface of the pharynx.
Branches: External and internal branches.
Supply: Sensory, motor, and parasympathetic innervation targeting the epiglottis, root of the tongue, and upper portions of the larynx.
Related parts of the anatomy
Origin
The superior laryngeal nerve originates from the inferior ganglion of the vagus nerve. The cell bodies for its sensory fibers are located in the inferior ganglion and travel to the nucleus solitarius. Motor and parasympathetic fibers cell bodies are located in the nucleus ambiguus and dorsal vagal nucleus, respectively.
Course
The superior laryngeal nerve runs inferiorly, posterior to the internal carotid artery and on the lateral surface of the pharynx. It travels close to the greater horn of the hyoid bone where it splits.
Branches
The superior laryngeal nerve splits to form two branches. The internal branch of the superior laryngeal nerve penetrates the thyrohyoid membrane to enter the internal aspect of the larynx. The external branch of the superior laryngeal nerve runs down the lateral surface of the inferior pharyngeal constrictor muscle.
Supplied Structures
The superior laryngeal nerve is a mixed nerve supplying sensory, motor, and parasympathetic innervation to tissues in the upper laryngeal region.
The internal branch of the superior laryngeal nerve penetrates the interior of the larynx. It carries with it sensory, motor and parasympathetic fibers.
—General visceral sensory fibers from the root of the tongue, epiglottis, laryngopharynx, esophageal opening, and all mucosa of the larynx, at or above the vocal folds, are conveyed by the internal branch of the superior laryngeal nerve.
—Special visceral sensory fibers from the root of the tongue and epiglottis convey taste sensation via the internal laryngeal branch of the superior laryngeal nerve.
—Parasympathetic fibers traveling down the superior laryngeal nerve will target glandular tissue and blood vessels in the mucosa of many of these tissues.
The external branch of the superior laryngeal nerve stays superficial to the larynx, traveling down along the lateral surface of the inferior pharyngeal constrictor muscle to the cricothyroid muscle. This branch of the superior laryngeal nerve is a branchial motor nerve that innervates both the inferior pharyngeal constrictor and the cricothyroid muscles.
List of Clinical Correlates
—Cough reflex
—Hoarseness
—Superior laryngeal nerve palsy
