1166 



THE ORGANS OF VOICE AND RESPIRATION 



angle in front, forming a vertical projection in the midline, which is prominent 

 above and called the pomum Adami (praminentia larynyea). This prominence 

 is subcutaneous, is more distinct in the male than in the female, and is often 

 separated from the integument by a bursa, the bursa subcutanea prominentiae 

 laryngeae. The anterior borders of the alae of the thyroid cartilage which are 

 continuous below are separated above by a V-shaped notch, the thyroid notch 

 (incisura thyroidea [superior^. The posterior borders are free, rounded, and some- 

 what thickened, and are extended in the form of superior and inferior r-m-miQ 

 The outer surface of each ala (Fig. 881) presents an oblique ridge (Uiiea obliqua), 

 which passes downward and forward from a tubercle situated near the root of the 

 superior cornu. the superior tubercle (tuberculum thyroideum superius\ to a small 

 tubercle near the anterior part of the lower border, the inferior tubercle (tuberculum 

 thyroideum inferius). This ridge gives attachment to the Sternothyroid and Thyro- 

 hyoid muscles, and the portion of cartilage included between it and the posterior 

 border gives attachment to part of the Inferior constrictor muscle. 



TRACHEA 



OESOPHAGUS 



THYROID 



GLAND 



STERNOTHYROIO 

 MUSCLE 

 STERNUM 

 THYROID 

 INNOMINATE 

 ARTERY 



FIG. 880. Sagittal section of a man twenty-one years of age 

 (After W. Braune.) 



FIG. 881. Side view of the thyroid and 

 cricoid cartilages. 



The inner surface (Fig. 882) of each ala is smooth, slightly concave, and covered 

 by the mucous membrane of the outer wall of the sinus pyriformis above and 

 behind; but in front, in the receding an^le formed by the junction of the ahe, 

 are attached the epiglottis, the true and false vocal cords, the Thyroarytenoid 

 and Thyroepiglottidean muscles, and the thyroepiglottidean ligament. 



The upper border (Fig. 881) is sinuously curved" being concave at its posterior 

 part, then rising into a convex outline in front; it gives attachment throughout 

 its whole extent to the thvrohvoid membra.. 



The lower border (Fig. 882) is nearly straight in front, but behind, close to the 

 cornu , it is concave, the two parts being separated by the inferior tubercle. A small 

 part of it, in and near the median line, is .connected to the cricoid cartilage by the 



