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 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. The
vocal muscle is the upper portion of the thyroarytenoid muscle which is primarily involved in producing speech. 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,
thyroepiglottic muscle,
thyreoepiglotticus or
thyroepiglottic, and are sometimes described as a separate muscle. A few fibers extend along the wall of the ventricle from the lateral wall of the
arytenoid cartilage to the side of the epiglottis and constitute the
ventricularis muscle. ==Function==