166 VISCERAL ANATOMY. 



Describe the Thyroid Cartilage. The Thyroid or shield-like cartilage 



consists of two Alee or wings,<* united in front at an acute angle, the highest 



portion of its front being called the Pomum Adami, Adam's apple. Its 



Inner Surface, gives attachment to the true and false vocal cords, the 



epiglottis, thyro-arytenoid and thyro-epiglottidean muscles, and the thyro- 



epiglottic ligament. 



Outer Surface, affords attachment to the sterno- 

 thyroid, thyro-hyoid and inferior constrictor mus- 

 cles ; the first two being attached along its oblique 

 ridge. 



Upper Border, is curved irregularly, and gives at- 

 tachment to the thyro-hyoid membrane. 

 Lower Border, gives attachment to the crico-thyroid membrane in the 



median line and on each side to the crico-thyroid muscle. 

 Posterior Border of each wing ends above and below in Cornua (horns), 



and gives attachment to the stylo- and palato-pharyngeus muscles. 

 Superior Cornu of each side affords attachment to the thyro-hyoid ligament. 

 Inferior Cornu of each side articulates with the cricoid cartilage by a small 

 oval facet. (See * and c, Fig. 80.) 



Describe the Cricoid Cartilage. The Cricoid, or ring-like cartilage, is 

 FIG. 81. placed below the thyroid, with its narrow part to the 



front. It has on each side 2 Articular Facets, one on the 

 upper margin posteriorly for the arytenoid cartilage, and 

 one near the lower margin for the inferior cornu of the 

 thyroid cartilage. Its 



Outer Borders, give attachment to the crico-arytenoideus 

 posticus muscle, and the longitudinal fibres of the oesophagus. 

 Upper Border, affords attachment to the crico-thyroid membrane and the 



crico-arytenoidei laterales muscles. 



Lower Border, is connected to the upper ring of the trachea by fibrous 

 membrane. 



Describe the Arytenoid Cartilages. The Arytenoid, or pitcher like 

 cartilages, are 2 in number, pyramidal -shaped, and situated on the upper mar- 

 gin of the cricoid cartilage posteriorly, closing in the back of the larynx. 

 Each cartilage has 3 surfaces, 2 angles, a base and an apex. The 



Anterior Surface, gives attachment to the false vocal 

 FIG. 82. chord, and the thyro-arytenoideus muscle. 



Anterior Angle, gives attachment to the true vocal chord 



and the thyro-arytenoideus muscle. 

 Posterior Surface, has attached to it the arytenoideus. 



