Thyroarytenoid muscle

The thyroarytenoid muscle is a broad, thin muscle that forms the body of the vocal fold and that supports the wall of the ventricle and its appendix. It functions to relax the vocal folds.

Origin and insertion

It arises in front from the lower half of the angle of the thyroid cartilage, and from the middle cricothyroid ligament.

Its fibers pass backward and laterally, to be inserted into the base and anterior surface of the arytenoid cartilage.

Parts of thyroarytenoid

The lower and deeper fibers of the muscle can be differentiated as a triangular band which is inserted into the vocal process of the arytenoid cartilage, and into the adjacent portion of its anterior surface; it is termed the Vocalis, and lies parallel with the vocal ligament, to which it is adherent.

A considerable number of the fibers of the thyroarytenoid muscle are prolonged into the aryepiglottic fold, where some of them become lost, while others are continued to the margin of the epiglottis. They have received a distinctive name, thyreoepiglotticus or thyroepiglottic, and are sometimes described as a separate muscle.