The vocal cords. The vocal cords correspond to folds of the mucosa of the larynx. They are stretched between the arytenoid cartilage (above) and the thyroid cartilage (below). The vocal cords are supported by another pair of folds, the ventricular bands. The vocal cords are in an open position during breathing, and closed during phonation, vibrating as air passes through and thus allowing sounds to be produced. The transition between these two states is made possible by several muscles: the lateral cricoarytenoid muscles (on the sides of the cricoid cartilage) and posterior cricoarytenoid muscles (above the cricoid cartilage), the arytenoid muscle (below the cricoid cartilage). Contraction of the posterior cricoarytenoid muscles moves the thyroid cartilage, separating the vocal cords. Conversely, contraction of the lateral cricoarytenoid muscles or the arytenoid muscle brings the vocal cords together. The vocal muscles (or thyroarytenoids), running along the vocal cords, ensure their t