Cricoarythenoid Muscle

Description

Posterior laryngeal anatomy is presented with the cricoid cartilage inferiorly and the paired arytenoid cartilages perched on its superior lamina at the cricoarytenoid joints. Between these cartilages, the posterior cricoarytenoid muscles occupy the posterior surface of the cricoid, their fascicles running superolaterally to insert on the muscular processes of the arytenoids. Superior to the cricoid, the posterior aspect of the thyroid cartilage frames the laryngeal inlet, while the vocal folds extend anteromedially from the vocal processes toward the thyroid cartilage. Mucosa, ligaments, and membranes are distinguished from muscle by color contrast. Functionally, the posterior cricoarytenoid is the only muscle that abducts the vocal folds, rotating the arytenoids laterally and widening the rima glottidis for breathing. Denervation in recurrent laryngeal nerve palsy classically leaves the posterior cricoarytenoid weak or silent, predisposing to paramedian vocal fold position and exertional dyspnea or stridor, a pattern best understood from a posterior view of the cricoarytenoid joint axis and muscular process. Small muscle. Big consequence. Use this plate in laryngeal anatomy and phonation teaching, otolaryngology training modules on vocal fold immobility, and medical publishing figures that need clear differentiation of laryngeal cartilages, ligaments, and intrinsic muscles in posterior perspective. Anatomical accuracy verified by SciePro's Medical Advisory Board.