Posterior Cricoarytenoid Muscle

Description

Centered on the posterior surface of the larynx, the paired posterior cricoarytenoid muscles arise from the broad lamina of the cricoid cartilage and run superiorly and laterally to insert on the muscular process of each arytenoid cartilage. The cricoid forms a complete ring inferior to the thyroid cartilage, with the arytenoids perched on its superoposterior rim at the cricoarytenoid joints. Adjacent intrinsic muscles are implied by the keywords and description, including the thyroarytenoid along the medial wall of the larynx and the cricothyroid spanning from the anterolateral cricoid to the inferior border and horn of the thyroid cartilage. The posterior cricoarytenoid sits posterior to the blue tinted vocal fold region and deep to the posterior laryngeal mucosa. Clear landmarks. Functionally, this is the sole abductor of the vocal folds, rotating the arytenoid cartilages laterally to open the rima glottidis, so the anatomic relationship between the cricoid lamina, arytenoid muscular process, and cricoarytenoid joint is the point. Bilateral recurrent laryngeal nerve injury can paralyze both posterior cricoarytenoids, leaving the cords near the midline and producing inspiratory stridor and airway compromise, a scenario discussed in thyroidectomy counseling and postoperative airway assessment. Unilateral denervation shifts glottic mechanics toward hoarseness, but the airway usually remains adequate. Otolaryngology and speech science courses use this view to teach intrinsic laryngeal muscle actions and to contrast abduction by posterior cricoarytenoideus with adduction by lateral cricoarytenoid and interarytenoids. It also fits surgical atlases and anesthesia texts covering intubation-related laryngeal injury, posterior glottic stenosis, and frameworks for interpreting laryngeal electromyography. Anatomical accuracy verified by SciePro's Medical Advisory Board.