The cricovocal membrane is a thin sheet of fibroelastic tissue that slopes upward and inward from each side of the cricoid arch. The superficial surface of each membrane is covered by the lateral cricoarytenoid muscle and the thyroarytenoid muscle, including the vocalis. Its deep surface is lined with the mucous membrane of the interior of the larynx. It is triangular in outline. The lower border is oblique, and is attached to the sloping, upper margin of the cricoid arch. The anterior border is partly continuous with the cricothyroid ligament, and, above that, is attached to the deep surface of the thyroid cartilage near the anterior angle. The superior border is divisible into two parts: the posterior part is attached to the lower surface of the vocal process of the arytenoid cartilage; the anterior part is longer, and is the free edge that forms the vocal ligament.