BRANCHES OF THE INTERNAL MAXILLARY ARTERY. 615 



the bone, and ramifies in the meatus and on the tympanic 

 membrane. 



c. The SMALL MIDDLE MENINGEAL BRANCH begins near the to dura 

 skull, and courses through the foramen ovale with the inferior mater - 

 maxillary nerve : it ramifies in the dura mater in the middle fossa 

 of the skull. 



Another small branch springs from the dental artery or from the Branch with 

 internal maxillary trunk, and accompanying the lingual nerve, ends J!"^ 11 

 in the cheek and the mucous membrane of the mouth. 



The branches from the second part of the artery (between the Branches of 

 temporal and external pterygoid muscles) are distributed to the |re P&r 

 temporal, masseter, buccinator, and pterygoid muscles. 



The DEEP TEMPORAL ARTERIES are two in number, anterior and to the 

 posterior, and ascend on the side of the skull beneath the temporal 

 muscle. The posterior anastomoses with the middle temporal 

 branch of the superficial temporal artery ; the anterior communi- 

 cates, through the malar bone, with branches of the lachrymal artery. 



The MASSETERIC ARTERY is directed outwards with the nerve of to the 

 the same name behind the tendon of the temporal muscle, and 

 passing through the sigmoid notch, enters the deep surface of the 

 masseter muscle. Its branches anastomose with the other offsets 

 to the muscle from the external carotid trunk. 



The BDCCAL BRANCH quits the artery near the upper jaw, and 

 descends beneath the insertion of the temporal muscle with its com- 

 panion nerve : it is distributed to the buccinator muscle and other 

 structures of the cheek, joining branches of the facial artery. 



The PTERYGOID BRANCHES are uncertain in their position and to pterygoid 

 number ; whether derived from the trunk or some of the branches musc 

 of the internal maxillary, they enter the two pterygoid muscles. 



Of the branches that arise from the artery in the third part of its Branches of 

 course, viz. in the spheno-maxillary fossa, only one, the posterior * 

 dental, will be now described. The remainder will be examined now seen 

 with the superior maxillary nerve and Meckel's ganglion ; they are 

 infra-orbital, descending palatine, spheno-palatim, Vidian, and 

 pterygo -pa latine . 



The POSTERIOR DENTAL BRANCH arises as the artery enters the is ]*| ri 

 spheno-maxillary fossa, and descends with a tortuous course on the dental, 

 zygomatic surface of the upper jaw, along with a small branch of 

 the superior maxillary nerve. Its branches mostly enter the canals 

 of the bone and supply the upper molar and bicuspid teeth, as well 

 as the lining membrane of the antrum ; some external offsets are 

 furnished to the gum. 



The INTERNAL MAXILLARY VEIN IS a short trunk, often double, Internal 



which leaves the hinder part of the pterygoid plexus, and runs back- JJJri'irises 

 wards, beneath the jaw with the first part of the internal maxillary from 

 artery, to join the superficial temporal vein in the parotid gland. 



The pterygoid plexus is an extensive network of veins surrounding pterysoid 

 the internal maxillary artery and the pterygoid muscles. Into it ple> 

 the veins corresponding to the branches of the artery empty them- 

 selves and it communicates with the cavernous sinus in the interior tributaries, 



