Internal Branch of Superior Laryngeal Nerve

Origin

The internal branch of the superior laryngeal nerve originates near the tip of the greater horn of the hyoid bone, lateral to the pharynx and posterior to the carotid arteries.

Course

From its origin, the internal branch of the superior laryngeal nerve runs anteriorly along the surface of the thyrohyoid membrane with the superior laryngeal artery. They both pierce the thyrohyoid membrane at which point the internal laryngeal nerve splits into terminal rami.

Branches

There are no named branches.

Supplied Structures

The internal branch of the superior laryngeal nerve is a mixed nerve supplying sensory and parasympathetic innervation for upper larynx and surrounding tissues.

Special sense afferents convey information from taste receptors on the epiglottis and root of the tongue back to the brainstem.

General visceral afferents convey information from the mucosa of the laryngeal surface of the epiglottis, the true vocal folds, the false vocal folds, the aryepiglottic folds, the arytenoid cartilage, the anterior laryngopharynx, and the upper esophageal sphincter back to the brainstem.

Parasympathetic fibers run through the internal branch of the superior laryngeal nerve to reach vasculature and glands in the root of the tongue, epiglottis, upper larynx, laryngopharynx, and upper esophageal region.

List of Clinical Correlates

—Cough reflex