256 THE ORGANS OF DIGESTION 



anterior half of the tongue drain into the submaxillary 

 nodes. Those draining the posterior half end in the 

 deep cervical nodes; along the internal jugular vein. 



Nerves of Tongue. (See Nerve System, pages 374 

 and 406.) 



The, Palate. The palate forms the roof of the 

 mouth, and consists of a front part or hard, and a 

 back part or soft palate. The periosteum of the hard 

 palate (see Bones) is covered by and intimately con- 

 nected with the mucous membrane of the mouth. 

 In the middle line is a raphe ending in front at a 

 small papilla, which marks the anterior palatine fossa 

 which receives the terminal part of the anterior 

 palatine and nasopalatine nerves. The mucous mem- 

 brane is pale and corrugated, covered with squamous 

 epithelium, and furnished with a number of palatal 

 glands which lie between it and the bone. 



The soft palate partially separates the mouth and 

 pharynx. It consists of muscular, connective, and 

 adenoid tissue, with vessels, nerves, and mucous 

 glands, all enclosed in a fold of mucous membrane. 

 Above it is joined to the back of the hard palate; 

 laterally it blends with the pharynx; below it is free; 

 in front it is concave, with a median ridge; and behind 

 it is convex. Its mucous membrane is continuous with 

 that of the roof of the mouth and of the posterior nares. 



From its lower border a conical process depends, 

 the uvula, from whose base descend the pillars of the 

 soft palate, the anterior, formed by the palaloglossi 

 muscles, to the sides of the base of the tongue; the 

 posterior, formed by the palatopharyngei, to the sides 

 of the pharynx. These pillars are covered by mucous 

 membrane and separated below by the tonsil, the 

 space being called the isthmus of the fauces. 



The tonsils (tonsilla palatina) are two in number, 

 situated on each side of the fauces, and lie between 

 the anterior and posterior palatine pillars, and are 

 about J inch long and \ inch wide and thick, but vary 

 much in size. 



