MOUTH 367 



the alveolar portions of the maxilla and mandible, whilst 

 posteriorly it is continued over the pharynx. The muscles 

 which traverse the fatty layer are chiefly the zygomaticus, 

 the risorius, and the posterior fibres of the platysma. The 

 parotid duct pierces the inner three layers of the cheek, and 

 opens into the vestibule of the mouth opposite the second 

 molar tooth of the maxilla. 



Gingivse et Dentes. The mucous membrane of the gums 

 is smooth, vascular, and firmly bound down to the subjacent 



Uvula 



Pharyngo- 

 palatine arch 



Tonsil 



Glosso-palatine 

 arch 



Posterior wall of 

 oral pharynx 



Tongue 



FIG. 147. Isthmus of the Fauces as seen through the widely opened Mouth. 

 The tonsils in the subject from which this drawing was made were 

 somewhat enlarged. 



periosteum of the alveolar portions of the jaws by a stratum 

 of dense connective tissue. It is continuous on the one 

 hand with the mucous membrane of the lips and cheeks, 

 and on the other with the mucous membrane of the mouth 

 proper. The gums closely embrace the necks of the teeth. 



In the adult the teeth in each jaw number sixteen. From 

 the median line posteriorly, on each side, they are the two 

 incisors, the canine, the two prsemolars, the three molars. 



Floor of the Mouth. The mucous membrane is reflected 

 from the inner aspect of the mandible to the side of the 

 tongue, but in the anterior part of the mouth the tongue lies 



