Book 4 - Self Instructional Manual for Cancer Registrars - SEER ...

LarynxThe larynx or voice box is a small but complex structure situated in front of the hypopharynx andcontiguous with the upper end of the trachea. The larynx consists of nine pieces of cartilage. Thethree single and more prominent pieces are:• Thyroid cartilage (Adam's apple)• Epiglottis which has a hinge-like action and forms a kind of lid over the opening of the larynxwhen swallowing takes place• The cricoid (signet-ring) cartilage, so named because it resembles a signet ring in shape. Thecricoid cartilage forms the inferior border of the larynx.In addition there are three paired cartilages:• Arytenoid cartilages (jar-like)• Corniculate cartilages (horn-like)• Cuneiform cartilages (wedge-like)These cartilages are united by joints strengthened by various membranes and ligaments. The mucousmembrane lining of the larynx forms two horizontal folds, the false vocal cords. Below these are thetrue vocal cords which are fibrous bands stretched across the hollow interior of the larynx. The spacebetween the true vocal cords is called the glottis. Air forced through these cords produces sound.Figure 17A. LARYNX/ zoo.,oo.,,.._.. I/::-:::?IlgL Z4 i °"°0""/: //0i ,........... 'I//7//._ j I143