SPLANCHNOLOGY. 189 



raanent teeth. Fig. 33, teeth of a grown man. Fig. 34, the posterior molar 

 or wisdom teeth. 



4, The Palate. The palate is composed anteriorly of the palatine pro- 

 cesses of the superior maxillary and palatine bones, covered above by the 

 mucous membrane of the nose, and below by the lining membrane of the 

 "mouth. This portion is the hard palate, and separates the mouth from the 

 nose. Behind it is a membranous portion called the soft palate, which 

 partially separates the mouth from the upper part of the pharynx. The 

 portion of the lining membrane of the mouth which covers the hard palate 

 has a hard cartilaginous feeling, and is not so sensitive as the other parts. 

 It has a ridge in its centre just below the middle palatine suture, and from 

 each side there are transverse ridges extending to the alveolar processes. 

 This arrangement is more evident anteriorly. Beneath this membrane, 

 especially at its posterior part, the muciparous glands are very abunda,nt 

 and close set. 



The soft palate, velum j'aldti, is continuous with the posterior margin of 

 the hard palate, and is stretched across the back part of the mouth from 

 one side to the other and obliquely downwards and backwards. Its free 

 inferior margin offers in its centre a projection about half an inch or more 

 in length, and called the uvula. From each side of the latter there proceed 

 two crescentic doublings of the lining membrane of the mouth called the 

 lateral half arches of the palate. Of these the anterior is the more distinct. 

 The tonsils are contained in the depression between these two duplicatares. 

 The muscles of the palate are, first, the constrictor isihmi faucium, arising 

 fi-om the middle of the soft palate, and inserted into the side of the tongue 

 near its root. It tends to close the opening between the mouth and the 

 pharynx. Second, the i^alalo-pharyngeus^ a small fasciculus within the 

 duplicature forming the posterior lateral half arch. Extending between the 

 soft palate and the pharynx, it serves to draw the former downwards. 

 Third, the circumflexus or tensor palati behind the pterygoid process of the 

 sphenoid bone. It spreads out or extends the palate. Fourth, the levator 

 palati on the inner side of the last. It arises from the point of the petrous 

 bone, and attached to the soft palate, draws it upwards. Fifth, the azygos 

 uvulce, in the centre of the soft palate and of the uvula. It arises from the 

 ])osterior pointed termination of the middle palatine suture, and serves to 

 draw the uvula upwards, and to diminish the vertical breadth of the soft 

 palate. 



PL 127, fig. 5, muscles of the palate and posterior side of the pharynx : 

 ', levator palati; ", tensor palati; '•'', azygos uvula?; ', glosso-palatine mus- 

 cle ; ', <'onstrictor isthmi ; ", posterior crico-arytenoid muscle ; ', transverse 

 and oVjlique arytenoid muscles. Fig. 6, palatine muscles: ', external ptery- 

 goid; ', levator palati ; "•*, tensor palati ; ', azygos uvulae; ', upper end of 

 the constrictor isthmi. 



5. Glands of the Mouth. The principal glands of the mouth are for 

 the purpose of secreting saliva, a substance essential to the proper mastica- 

 tion, deglutition, and digestion of food. They consist of the parotid, the 

 submaxillary, and the sublingual. 



89S 



