cricoarytenoidmusklene

The cricoarytenoid muscles (cricoarytenoidei) are two intrinsic laryngeal muscles that act on the arytenoid cartilages relative to the cricoid cartilage. They are essential for regulating the glottic opening and thus influence both voice production and airway patency. In common usage, the term refers to the lateral cricoarytenoid and the posterior cricoarytenoid muscles, which pair with other intrinsic laryngeal muscles to modulate the vocal folds.

Lateral cricoarytenoid muscle: this muscle originates from the upper border of the cricoid arch and inserts on the muscular process of the arytenoid. It adducts the vocal folds by drawing the arytenoid cartilages medially, contributing to vocal fold closure during phonation. Innervation is via the recurrent laryngeal nerve.

Posterior cricoarytenoid muscle: this muscle originates from the posterior surface of the cricoid lamina and inserts on the posterior aspect of the arytenoid’s muscular process. It abducts the vocal folds by rotating the arytenoid cartilages laterally, thereby opening the glottis and aiding airway protection. Innervation is via the recurrent laryngeal nerve.

Other intrinsic laryngeal muscles, such as the inter Arytenoid group, also influence glottal closure but are not classified as cricoarytenoid muscles. The cricoarytenoid muscles receive blood supply from branches of the superior and inferior laryngeal arteries.

Nerve supply to these muscles is primarily through the recurrent laryngeal nerve, a branch of the vagus nerve. Dysfunction of this nerve can affect voice and airway, with unilateral palsy causing hoarseness and bilateral palsy risking impaired ventilation.