Thyroarytenoid Muscle in a Larynx Cross Section, Lateral View

Description

Running lateral to the vocal ligament, the thyroarytenoid muscle forms the bulk of the true vocal fold, extending from the inner surface of the thyroid cartilage (near the angle and adjacent anterior commissure) posteriorly to the anterolateral surface and vocal process of the arytenoid cartilage. Medially, its vocalis portion hugs the free edge of the glottis, while laterally it blends with paraglottic connective tissue and fascia along the inner thyroid lamina. Superior to the true fold, the ventricular fold and laryngeal ventricle are implied, and inferiorly the conus elasticus spans toward the superior border of the cricoid cartilage. Small fiber continuations consistent with the thyroepiglotticus track superiorly toward the epiglottis. Seeing the thyroarytenoid in profile matters because its shortening and medial bulking directly shape phonation: it lowers pitch and contributes to glottic closure while working in concert, and sometimes in opposition, with the cricothyroid. This relationship becomes clinically concrete in unilateral vocal fold paralysis after recurrent laryngeal nerve injury, where loss of thyroarytenoid tone produces a bowed, atrophic fold and a persistent phonatory gap. It is also the key intralaryngeal target for botulinum toxin in selected hyperfunctional voice disorders, and a structure you must respect during transoral or transcervical approaches that manipulate the vocal fold cover. Voice science modules, laryngeal anatomy labs, and otolaryngology teaching files use this cut to orient residents to the layered vocal fold model (mucosa, vocal ligament, thyroarytenoid) and to explain why medialization thyroplasty aims to restore the missing bulk of the paralyzed fold. Anatomical accuracy verified by SciePro's Medical Advisory Board.