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.

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.

Its main use is to draw the arytenoid cartilages forward toward the thyroid, thus relaxing and shortening the vocal folds.

But, owing to the connection of the deeper portion with the vocal fold, this part, if acting separately, is supposed to modify its elasticity and tension, while the lateral portion rotates the arytenoid cartilage inward, and thus narrows the rima glottidis by bringing the two vocal folds together.