Larynx USMLE, Limited Edition > Gross Anatomy > Gross Anatomy LARYNX • The larynx is the start of the lower respiratory tract. • Superiorly, the larynx is attached to the hyoid bone via connective tissues. • Three key functions of the larynx: • It conducts air from the pharynx to the trachea. • It prevents food and liquid from entering the lower respiratory tract. • It facilitates the production of speech. Key anatomical structures: Three larger, singular cartilages: • Thyroid cartilage – forms anterior and lateral walls; features the laryngeal prominence. • Cricoid cartilage – circular, forms base of larynx. • Epiglottis – "flap" that attaches to the internal surface of the thyroid cartilage, anteriorly, and projects posteriorly and superiorly over the opening of the larynx. - Upon swallowing, the flap closes off the entryway to the larynx, which prevents foods and liquids from entering the lower respiratory tract. Three paired sets of smaller cartilages: • Arytenoid cartilage – articulates with cricoid cartilage posteriorly. • Corniculate cartilage – sits on arytenoid cartilages. • Cuneiform cartilage – sits anterior to corniculate cartilages; very small, wedge-shaped. Membranes and connective tissues: • Thyrohyoid membrane - connects the thyroid cartilage and hyoid bone. • Cricothyroid ligament - extends superiorly from the cricoid cartilage to the thyroid and arytenoid cartilages. 1 / 2 • Vocal ligament - thickened superior edge of the cricothyroid ligament comprises the vocal ligament; known as the "true" vocal cord because it facilitates sound production. • Rima glottides - opening between the vocal cords. During sound production, laryngeal muscles contract to rotate the arytenoid cartilages and alter the opening between the true vocal cords. • Quadrangular membrane - connects the lateral sides of the epiglottis to the arytenoid cartilages. - Free edges of the quadrangular membrane thicken to form the: Aryepiglottic ligament, superiorly The vestibular ligament, inferiorly The vestibular ligament and its mucosal covering are often referred to as the "false vocal cord"; it does not participate in sound production. Clinical correlations: Laryngitis is inflammation of the vocal cords, which can stem from infectious or non-infectious causes (such as over- use). It typically results in hoarseness but severe swelling can block the airways. Powered by TCPDF (www.tcpdf.org) 2 / 2.