Thyroarytenoid Muscle, Gross Anatomy

Description

Running anteroposteriorly along the inner surface of the left thyroid cartilage lamina, the thyroarytenoid muscle is shown arising near the thyroid angle and coursing posteriorly to insert on the anterolateral aspect of the arytenoid cartilage, immediately lateral to the vocal ligament. Medially, its deeper vocalis fibers parallel the free edge of the true vocal fold, while more lateral bundles blend with the conus elasticus and lie deep to the thyroid cartilage. Superiorly the muscle approaches the level of the laryngeal ventricle, and inferiorly it sits above the cricothyroid ligament and the superior margin of the cricoid cartilage. Short, thick, and segmentally fibered. This is the workhorse of fine phonatory control: thyroarytenoid contraction shortens the vocal fold and increases its effective mass, counterbalancing cricothyroid-mediated lengthening, and the vocalis component can create localized changes in tension along the vibrating margin. Clinically, it is central to patterns seen in muscle tension dysphonia and to glottic insufficiency after recurrent laryngeal nerve paresis, where loss of thyroarytenoid bulk contributes to a persistent glottal gap and breathy voice. Surgeons and laryngologists also target this muscle in transoral injection laryngoplasty and in botulinum toxin techniques for selected hyperfunctional voice disorders. A practical landmark. Use this artwork in gross anatomy and head and neck courses, voice science and speech-language pathology teaching, and in otolaryngology publications discussing phonation mechanics, vocal fold medialization, and laryngeal electromyography targets in adult males. Anatomical accuracy verified by SciePro's Medical Advisory Board.