These are paired pyramidal shaped cartilages that are attached to the sloping superior border of the posterior lamina of the cricoid cartilage via the cricoarytenoid joint by a complex of muscles and ligaments. The positioning of the arytenoid cartilages play an important role in regulating pitch as well as the opening and closing of the vocal folds. Each cartilage has an apex, a base, an anterolateral surface, a vocal process and lateral muscular process. The corniculate cartilage is attached to the apex. The base forms the upper surface of the cricoarytenoid joint. The vocal ligament is attached to the anterior vocal process while the quadrangular membrane is attached to the roughened anterolateral aspect. The posterior cricoarytenoid muscle, thyroarytenoid muscle and lateral cricoarytenoid muscles are attached to the muscular process. The interarytenoid muscle inserts into the posterior surface of the arytenoid cartilage which is triangular, smooth and concave.