thyroarytenoid muscles, two broad, flat muscles lateral to the fibroelastic membrane of the larynx and the laryngeal entricles and saccules. Each muscle runs from a vertical line of origin on the lower half of the thyroid angle and adjacent external surface of the cricothyroid ligament to the anterolateral surface of the arytenoid cartilage. Some of the fibers may continue into the aryepiglottic fold and reach the margin of the epiglottis. They act as sphincters to the laryngeal vestibule and also narrow the laryngeal inlet. They are innervated by the recurrent laryngeal branches of the vagus nerves.
