External laryngeal nerve

External laryngeal nerve

Course and distribution of the glossopharyngeal, vagus, and accessory nerves. (External branch of superior laryngeal labeled at center right.)
Details
Latin ramus externus nervi laryngei superioris
From
 superior laryngeal nerve
Innervates cricothyroid muscle, pharyngeal plexus
Identifiers
Gray's p.912
Dorlands
/Elsevier		 r_02/12690066
TA A14.2.01.161
FMA 6243
Anatomical terms of neuroanatomy

The external laryngeal nerve is the smaller, external branch (ramus externus) of the superior laryngeal nerve. It descends on the larynx, beneath the sternothyroid muscle, to supply the cricothyroid muscle.

It functions to tense the vocal cords by activating the cricothyroid muscle, increasing pitch.

It gives branches to the pharyngeal plexus and the superior portion of the inferior pharyngeal constrictor, and communicates with the superior cardiac nerve behind the common carotid artery.

Clinical significance

The external branch is susceptible to damage during thyroidectomy or cricothyrotomy, as it lies immediately deep to the superior thyroid artery. The ability to produce pitched sounds is then impaired along with easy voice fatigability, (usually mono-toned voice). Damage to the superior laryngeal nerve leaves the vocal cord abducted and poses an aspiration risk.


External links