Transverse arytenoid muscle

At a glance

English

Transverse arytenoid muscle

Latin (TA2)

Musculus arytenoideus transversus

System

Muscle

Region

Neck

Side

Single, on the midline

About the transverse arytenoid muscle

The transverse arytenoid is an intrinsic muscle of the larynx and the only one that is not paired. It lies across the back of the larynx, behind the arytenoid cartilages and in front of the laryngopharynx. The oblique arytenoids lie directly on it, crossing each other in an X, and together the two are sometimes called the arytenoid muscle.

Its fibres run horizontally from the back surface and lateral margin of one arytenoid cartilage to the matching surface of the other. In doing so it fills the hollow on the back of each arytenoid. Its back surface is covered by the mucosa of the pharynx.

Contraction pulls the arytenoids towards each other along the top of the cricoid. This closes the rear part of the glottis, the gap between the arytenoids that stays open when only the front of the vocal folds meets. Complete closure of the vocal folds, needed for a clear voice, for coughing and for protecting the airway, relies on this action together with the lateral crico-arytenoid muscles.

Its nerve is the recurrent laryngeal branch of the vagus, and it receives fibres from both sides. Because it is easy to reach and responds well, recordings of its electrical activity are used during thyroid and other neck operations to confirm that the recurrent laryngeal nerve still works. Its blood comes from the laryngeal branches of the thyroid arteries.

Attachments, action and supply

Origin

Back surface and lateral margin of one arytenoid cartilage.

Insertion

Back surface and lateral margin of the opposite arytenoid cartilage.

Action

Draws the arytenoids together, closing the rear part of the glottis.

Nerve supply

Recurrent laryngeal nerve (vagus), from both sides.

Blood supply

Inferior laryngeal artery (from the inferior thyroid) and superior laryngeal artery (from the superior thyroid).