120 A MANUAL OF ANATOMY. 



and in the sublingual fossa of the inferior maxilla. It 

 rests upon the mylohyoid muscle, and has the geniohyo- 

 glossus muscle and the opposite gland at the inner side. 

 Behind, it comes in contact with the deep lobe of the sub- 

 maxillary gland. 



Its main duct is called the duct of Rivinus. It accom- 

 panies Wharton's duct and opens with it upon the top of 

 the same papilla in the mouth. 



Numerous smaller ducts from the anterior portion of 

 the gland open upon the floor of the mouth. 



The blood supply is from the sublingual (from the lin- 

 gual) and the submental (from the facial). 



The nerve supply is from the gustatory (lingual) and 

 sympathetic. 



The Internal Maxillary Artery. 



The internal maxillary artery is the larger branch of 

 bifurcation of the external carotid. It is given off behind 

 the neck of the lower jaw within the parotid gland. 



It follows a tortuous course forward and inward, passing 

 between the neck of the jaw and the internal lateral 

 ligament, then upward and forward across the front (exter- 

 nal surface) of the external pteryoid muscle, then turns 

 into the sphenomaxillary fossa, where it divides into its 

 terminal branches. The course of the artery divides it 

 into three portions, the maxillary, behind the neck of the 

 jaw ; the pterygoid, in connection with the pterygoid 

 muscle ; and the sphenomaxillary, within this fossa. 



Branches of the Internal Maxillary. Maxillary portion 

 or first portion. 



(1) The deep auricular. A small branch to the anterior 

 wall of the external meatus. 



(2) The tympanic branch, a very slender artery which 



