THE SOFT PALATE. l!77 



lips, and consist of an external cuticular, a central muscular, and 

 au internal mucous coat ; the latter is termed the buccal mem- 

 brane, and is provided with numerous small buccal glands, 

 similar to the labial ones, which open on its surface by straight 

 projecting pointlets ; a few larger ones are known as the nivu' 

 glands. On the buccal membrane of each side, near the third 

 upper molar tooth, is a papilla in which is the opening of the 

 duct of the parotid gland The gingivce, or gums, are reflections 

 of the buccal membrane, and contain dense fibrous tissue, con- 

 tinuous with the periosteum of the alveolar processes, with an 

 epithelial covering ; they embrace, without being attached to, 

 the necks of the teeth, and are reflected into the alveoli. The 

 chief arteries and veins of the cheek are the facial and the 

 coronaries. The nerves corne from the same source as those of 

 the lips. The cheeks by their muscles serve during mastication 

 to support the food, and press it between the molars. 



THE HARD PALATE. 



The hard palate, or mouth-roof, is bounded anteriorly by the 

 incisor teeth, posteriorly by the soft palate. It is firmly attached 

 to the bony palate, formed by the palatine bones and palatine 

 processes of the superior and premasillae. It consists of a dense 

 layer of mucous membrane, with a thick subjacent layer of fibrous 

 tissue. It is equally divided by a longitudinal groove corres- 

 ponding to the palatine suture, which originates anteriorly at the 

 base of a small tubercle. From this raphe spring transverse 

 ridges, which divide the palate into a number of arches with 

 their concavities backwards ; they become smaller posteriorly, 

 and are from seventeen to twenty in number. 



The palate is supplied with blood from the palatine arteries, 

 returned in a venous plexus, which forms a kind of erectile tissue 

 in the submucous layer. The sensory nerves come from the 

 superior maxillary division of the fifth pair. The hard palate 

 furnishes a fixed surface, against which the tongue can mani- 

 pulate the food 



THE SOFT PALATE. 



The soft palate, or velum pendulum palati, is the valvular 

 curtain suspended between the mouth and the pharynx, and it 

 consists of a double fold of mucous membrane, enclosing muscles, 

 glands, vessels, and nerves. It presents two surfaces and four 



