Internal Laryngeal Nerve

The internal laryngeal nerve is the internal branch (ramus internus) of the superior laryngeal nerve. It descends to the thyrohyoid membrane, pierces it in company with the superior laryngeal artery, and is distributed to the mucous membrane of the larynx.

Of these (sensory) branches some are distributed to the epiglottis, the base of the tongue, and the epiglottic glands; others pass backward, in the aryepiglottic fold, to supply the mucous membrane surrounding the entrance of the larynx, and that lining the cavity of the larynx as low down as the vocal folds.

A filament descends beneath the mucous membrane on the inner surface of the thyroid cartilage and joins the recurrent nerve.

Above the vocal folds the sensory innervation of the larynx is via the internal laryngeal nerve. Below the vocal folds it is by way of branches of the recurrent laryngeal nerve. The vocal fold itself receives dual innervation from both nerves.