NORMAL HISTOLOGY. 



goblet-cells. The minute groups of glands in the epiglottis lie em- 

 bedded within the pits and openings in its plate of cartilage. The 



true vocal cords are destitute of 

 FIG. 284. mucous glands. 



The cartilaginous frame- 

 work of the larynx consists prin- 

 cipally of hyaline cartilage ; to 

 this variety belong the thyroid, 

 the cricoid, and the greater part 

 of the arytenoid cartilages. 

 The epiglottis, the apex and 

 the processus vocales of the aryt- 

 enoid cartilages, together with 

 the cartilages of Wrisberg and 

 of Santorini, are formed of the 

 yellow elastic variety. The 

 little nodules embedded within the 

 lateral thyro-hyoid ligaments, the 

 cartilagines triticese, are some- 

 times composed of fibrous, at other 

 times of yellow elastic cartilage. 

 On the outer side fibrous connec- 

 tive tissue connects the peri- 

 chondrium with the surrounding 

 structures, the attachment of the muscles being effected by 

 tendinous tissue directly continuous with the investment of the 

 cartilage. 



The blood-vessels supplying the interior of the* larynx terminate 

 within the mucosa in capillary net-works beneath the epithelium ; in 

 those parts where papillae exist these are provided with vascular 

 loops. 



The lymphatics exist as a superficial net-work of small vessels 

 within the mucosa, and a deeper set, composed of much larger 

 channels, within the submucous tissue ; these latter vessels are of 

 exceptional size on the anterior surface of the epiglottis. The lym- 

 phoid character of the mucoca in certain localities has already 

 been noted ; local aggregations of such cells in the form of lymph- 

 follicles are encountered in man sometimes, and constantly in some 

 of the lower animals (dog, cat). 



The nerves distributed to the laryngeal mucous membrane are 

 composed principally of medullated fibres, although pale fibres are 

 present. 



Longitudinal section of epiglottis of child : 

 a. laryngeal surface ; b, glossal surface ; c , plate 

 of elastic cartilage ; d, acini of mucous glands. 



