Laryngeal nerve
Encyclopedia
Galen
Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...
's nerve, is a nerve
Nerve
A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...
originating from the vagus nerve
Vagus nerve
The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves...
. It comprises two branches, the cranial superior laryngeal nerve
Superior laryngeal nerve
The superior laryngeal nerve is a branch of the vagus nerve. It arises from the middle of the ganglion nodosum and in its course receives a branch from the superior cervical ganglion of the sympathetic....
, which leaves the vagus at the distal ganglion and passes ventrally to the larynx
Larynx
The larynx , commonly called the voice box, is an organ in the neck of amphibians, reptiles and mammals involved in breathing, sound production, and protecting the trachea against food aspiration. It manipulates pitch and volume...
supplying the cricothyroid muscle
Cricothyroid muscle
The cricothyroid muscle is the only tensor muscle of the larynx, aiding with phonation. It attaches to the anterolateral aspect of the cricoid and the inferior cornu and lower lamina of the thyroid cartilage, and its action tilts the thyroid forward to help tense the vocal cords...
and laryngeal mucosa, and the caudal recurrent laryngeal nerve
Recurrent laryngeal nerve
The recurrent laryngeal nerve is a branch of the vagus nerve that supplies motor function and sensation to the larynx . It travels within the endoneurium...
, which enters the larynx under the caudal edge of the cricopharyngeus muscle
Inferior pharyngeal constrictor muscle
The Inferior pharyngeal constrictor, the thickest of the three constrictors, arises from the sides of the cricoid and thyroid cartilage. Similarly to the superior and middle pharyngeal constrictor muscles, it is innervated by the vagus nerve , specifically, by branches from the pharyngeal plexus...
and innervates all of the muscles of the larynx except the cricothyroid
Cricothyroid muscle
The cricothyroid muscle is the only tensor muscle of the larynx, aiding with phonation. It attaches to the anterolateral aspect of the cricoid and the inferior cornu and lower lamina of the thyroid cartilage, and its action tilts the thyroid forward to help tense the vocal cords...
.
There are two subdivisions of the superior laryngeal nerve. These are internal
Internal laryngeal nerve
The internal laryngeal nerve is the internal branch 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....
(sensory) and external
External laryngeal nerve
The external laryngeal nerve is the smaller, external branch of the superior laryngeal nerve. It descends on the larynx, beneath the sternothyroid muscle, to supply the cricothyroid muscle....
(motor).