256 



ANATOMY FOR NURSES 



[Chap. XIV 



is bounded in front l)y the lips, on the sides by the cheeks, below 

 by the tongue, and above by the palate. 



The palate. — The palate consists of a hard portion in front 

 formed by bone, covered by mucous membrane, and of a soft 

 portion behind containing no bone. The hard palate forms the 

 partition between the mouth and nose ; the soft palate arches 

 backward and hangs like a curtain between the mouth and 

 the pharynx. Hanging from the middle of its lower border is a 

 pointed portion of the soft palate called the uvula (little 

 grape). 



Palatine arches. — From the base of the uvula on either side 

 there passes a curved fold of muscular tissue covered by mucous 

 membrane, which shortly after leaving the uvula is, as it were, 



split into two pillars, the 

 ^% one gcung outward, down- 



I % ward, and forward, passing 



to the side of the tongue, 

 the other outward, down- 

 ward, and backward to the 

 side of the pharynx. These 

 pillars are known respec- 

 tively as the anterior and the 

 posterior pillars of the fauces. 

 Tonsils. — In the lower 

 part of the triangular space 

 between the anterior and 

 posterior pillars on either 

 side lie the small masses of 

 lymphoid tissue called ton- 

 sils. They consist of a col- 

 lection of lymph nodules 

 held together by a distinct 

 capsule and covered on their 

 ex-posed surface by mucous 

 membrane. 



Function. — The function of the tonsils is imperfectly under- 

 stood. They may be a source of lymphocytes and leucocytes, or 

 they may act as filters and prevent the entrance of microorgan- 

 isms. Inflammation of the tonsils is called tonsillitis. 



Fig. 147. — The Soft P.\late and 

 Tonsillar Regions. (Gcrrish.) 



