THE LARYNX. 525 



The nerves come from the sympathetic and pneumo- 

 gastric. 



The lymphatics pass into the cervical glands. 



The thyroid, in the infant, descends as low as the thy- 

 mus gland. It not unfrequently suffers enlargement con- 

 stituting the disease called goitre, or bronchocele. 



Its function is yet unsettled, though it is regarded as a 

 diverticulum to the cerebral circulation. 



SECTION VII. 



THE LARYNX, OR ORGAN OF VOICE. 



The larynx is situated at the anterior part of the neck, 

 between the tongue and trachea, surmounting the respi- 

 ratory tube, and thus being connected with the organs of 

 respiration below, as well as with the pharynx or that of 

 deglutition above. It consists of cartilages, ligaments, mus- 

 cles, vocal chords, a lining mucous membrane and glands, 

 with blood-vessels, and nerves thus forming a great vari- 

 ety of structures, and an apparatus both curious and com- 

 plicated. 



Cartilages. The cartilages form the solid frame work, and 

 constitute the basis of 'the larynx. They are five in num- 

 ber, the thyroid, cricoid, two arytenoid, and p, Gt 153. 

 epiglottis. These, united, form the larynx, 

 a hollow box or musical case, whose cav- 

 ity is somewhat quadrangular and larger 

 above than below. 



The thyroid (0vpoj, shield, &>$, like) is 

 the largest of the cartilages, and occupies the anterior 

 and lateral portions of the larynx. It consists of two sym- 

 metrical parts called alee, which meet in front along the 

 median line, in an acute angle forming a prominence, 

 known under the name of pomum Adami. Each ala pre- 

 sents a broad quadrilateral plate which looks backward, 

 and on its posterior margin, at the superior and inferior 



FIG. 158 represents the Thyroid Cartilage, a Superior cornu. c Inferior 

 cornu. 6 Ala of left side, d Entering angle. 



