l8o NORMAL HISTOLOGY AND ORGANOGRAPHY. 



Blood Supply. The arteries are the lingual, 

 which branches to form (i) the dorsal lingual artery 

 which anastomoses freely with the tonsillar branch 

 of the facial, and (2) the ranine artery that passes 

 along the under surface. The veins are the ranine 

 and the dorsalis linguce that drain into the internal 

 jugular. 



Nerves. These are (i) the hypoglossal, the motor 

 nerve; (2) the lingual, from the inferior maxillary 

 of the fifth, which is accompanied by the chorda 

 tympani of the seventh, or facial; (3) the glosso- 

 pharyngeal, which supplies the taste buds; (4) the 

 internal laryngeal. Many fibers of the sympathetic 

 system mingle with these nerves. 



PHARYNX. 



The pharynx is the common passage for both 

 food and air. It is an expanded portion of the di- 

 gestive tube five inches in length and with seven 

 openings: one, the fauces from the mouth; two 

 posterior nares; two Hustachian tubes; one to the 

 trachea, and the orifice of the esophagus. 



The mucous membrane of the pharynx is lined 

 with stratified squamous epithelium, except in the 

 region of the posterior nares where the epithelium 

 is ciliated. In the submucosa there is a generous 

 supply of mucous and serous glands and lymphoid 

 tissue. The latter is particularly abundant in the 

 region of the posterior nares, forming in this location 

 the pharyngeal tonsils or adenoids. In early youth 

 the adenoids are prone to enlarge so as to obstruct 

 normal breathing, a condition that justifies their 

 removal. A rich supply of elastic longitudinal 



