The larynx extends from the laryngeal inlet to the inferior border of the cricoid cartilage. It lies opposite the third to sixth cervical vertebrae. The larynx contains 9 cartilages connected by joints, ligaments, and muscles. The thyroid cartilage is the largest and protects the larynx. The vocal cords lie within the larynx and are responsible for voice production. The larynx develops from the branchial arches and undergoes changes between infancy and adulthood.