Posterior Cricoarytenoid Muscle, Posterior View

Description

Arising from the broad posterior lamina of the cricoid cartilage, the paired posterior cricoarytenoid muscles course superolaterally to insert on the muscular process of each arytenoid cartilage. Fiber direction is oblique, running from an inferior, medial origin toward a superior, lateral insertion, placing the muscle belly directly posterior to the cricoarytenoid joint. Along the midline, the posterior cricoarytenoids lie adjacent to the interarytenoid region, while the thyroid cartilage sits more anterior and superior, with the hyoid bone superior to the laryngeal framework. Only abductors. Clinical relevance is straightforward: posterior cricoarytenoid is the sole abductor of the vocal folds, rotating the arytenoid cartilages laterally to open the rima glottidis during inspiration. Injury to the recurrent laryngeal nerve, after thyroidectomy, anterior cervical spine surgery, or from mediastinal malignancy, can denervate this muscle and leave the vocal folds near the midline, producing inspiratory stridor and airway compromise that differs from the breathy dysphonia of isolated adductor weakness. A posterior perspective also clarifies why cricoarytenoid joint fixation or posterior glottic stenosis can mimic neurogenic paralysis, even when the nerve is intact. Use this plate for head and neck anatomy teaching in gross anatomy and speech language pathology curricula, and for otolaryngology or anesthesia materials explaining glottic opening during respiration and the mechanism of bilateral vocal fold immobility. It also supports surgical atlases covering posterior laryngeal exposure, arytenoidectomy, and endoscopic management of posterior glottic stenosis. Anatomical accuracy verified by SciePro's Medical Advisory Board.