Lateral cricoarytenoid muscle


The lateral cricoarytenoid is an intrinsic muscle of the larynx. It attaches at the cricoid cartilage anteriorly, and at the arytenoid cartilage of the same side posteriorly. It is innervated by the recurrent laryngeal nerve. It acts to close the rima glottidis, thus closing the airway.

Anatomy

The muscle is directed obliquely superoposteriorly from its anterior attachment to its posterior attachment.

Attachments

The muscle's anterior attachment is onto the superior border of the arch of the cricoid cartilage.
Its posterior attachment is onto the anterior aspect of the muscular process of the ipsilateral arytenoid cartilage.

Innervation

The muscle receives motor innervation from the recurrent laryngeal nerve.

Actions/movements

The muscle rotates the arytenoid cartilage medially.

Function

The muscle closes the rima glottidis, adducting the apices of the vocal process to close the ligamentous part of rima glottidis. It thus functions to close the airway.
It also shortens and slackens the vocal cords.