INTERNAL MAXILLARY. 455 



supraorbital and frontal arteries, its branches being directed from before back- 

 wards. 



The posterior temporal, larger than the anterior, curves upwards and back- 

 wards along the side of the head, lying above the temporal fascia, and inoscu- 

 lates with its fellow of the opposite side, and with the posterior auricular and 

 occipital arteries. 



The temporal artery, as it crosses the zygoma, is covered by the Attrahens 

 Aurem muscle, and by a dense fascia given off from the parotid gland; it is also 

 usually crossed by one or two veins, and accompanied by branches of the fascial 

 and auriculo-temporal nerves. Besides some twigs to the parotid gland, the 

 articulation of the jaw, and the Masseter muscle, its branches are the 



Transverse Facial. Middle Temporal. 



Anterior Auricular. 



The transverse facial is given off from the temporal before that vessel quits 

 the parotid gland; running forwards through its substance, it passes transversely 

 across the face, between Steno's duct and the lower border of the zygoma, and 

 divides on the side of the face into numerous branches, which supply the parotid 

 gland, the Masseter muscle, and the integument, anastomosing with the facial 

 and infraorbital arteries. This vessel rests on the Masseter, and is accompanied 

 by one or two branches of the facial nerve. It is sometimes a branch of the 

 external carotid. 



The middle temporal artery arises immediately above the zygomatic arch, and 

 perforating the temporal fascia, supplies the Temporal muscle, anastomosing 

 with the deep temporal branches of the internal maxillary. It occasionally 

 gives off an orbital branch, which runs along the upper border of the zygoma, 

 between the two layers of the temporal fascia, to the outer angle of the orbit. 

 This branch supplies the Orbicularis, and anastomoses with the lachrymal and 

 palpebral branches of the ophthalmic artery. 



The anterior auricular branches are distributed to the anterior portion of the 

 pinna, the lobule, and part of the external meatus, anastomosing with branches 

 of the posterior auricular. 



Surgical Anatomy. It occasionally happens that the surgeon is called upon to perform the 

 operation of arteriotomy upon this vessel in cases of inflammation of the eye or brain. Under 

 these circumstances, the anterior branch is the one usually selected. If the student will con- 

 sider the relations of the trunk of this vessel, as it crosses the zygomatic arch, with the surround- 

 ing structures, he will observe that it is covered by a thick and dense fascia, crossed by one or 

 two veins, and accompanied by branches of the fascial and temporo-auricular nerves. Bleeding 

 should not be performed in this situation, as much difficulty may arise from the dense fascia 

 over the vessel preventing a free flow of blood, and considerable pressure is requisite afterwards 

 to repress the hemorrhage. Again, a varicose aneurism may be formed by the accidental open- 

 ing of one of the veins in front of the artery ; or severe neuralgic pain may arise from the opera- 

 tion implicating one of the nervous filaments in the neighborhood. 



The anterior branch is, on the contrary, subcutaneous, is a large vessel, and as readily com- 

 pressed as any other portion of the artery ; it should consequently always be selected for the 

 operation. 



The Internal Maxillary (Fig. 277), the larger of the two terminal branches of 

 the external carotid, passes inwards, at right angles from that vessel, to the 

 inner side of the neck of the condyle of the lower jaw, to supply the deep struc- 

 tures of the face. At its origin, it is imbedded in the substance of the parotid 

 gland, being on a level with the lower extremity of the lobe of the ear. 



In the first part of its course (maxillary portion), the artery passes horizon- 

 tally forwards and inwards, between the ramus of the jaw and the internal 

 lateral ligament. The artery here lies parallel with the auriculo-temporal 

 nerve ; it crosses the inferior dental nerve, and lies beneath the narrow portion 

 of the External Pterygoid muscle. 



In the second part of its course (pterygoid portion), it runs obliquely for- 

 wards and upwards upon the outer surface of the External Pterygoid muscle, 



