THE EXTERNAL CAROTID ARTERY 601 



Besides some twigs to the parotid gland, the articulation of the mandible, and 

 the Masseter muscle, its branches are: 



. 



Transverse facial. Anterior auricular. 



Middle temporal. Anterior temporal. 



Orbital. Posterior temporal. 



The transverse facial branch (a. transversa faciei) is given off from the tem- 

 poral before that vessel quits the parotid gland; running forward through its 

 substance, it passes transversely across the face, between the parotid 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 integu- 

 ment, anastomosing with the facial, masseteric, 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 (a. temporalis media) arises immediately above 

 the zygomatic arch, and, perforating the temporal fascia, gives branches to 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, which may arise directly from the superficial 

 temporal artery, supplies the Orbicularis palpebrarum, and anastomoses with 

 the lacrimal and palpebral branches of the ophthalmic artery. 



The orbital artery (a. zygomaticoorbitalis) comes off from the temporal just 

 above the zygoma and is distributed to the upper orbital margin. 



The anterior auricular branches (rami auriculares anteriores} are distributed to 

 the anterior portion of the pinna, the lobule, and part of the external meatus, 

 anastomosing with branches of the posterior auricular. 



The anterior temporal runs tortuously upward and forward, to the forehead, 

 supplying the muscles, integument, and pericranium in this region, and anasto- 

 moses with the supraorbital and frontal arteries. The terminal portion of the 

 anterior branch is called the frontal artery (ramus frontalis). 



The posterior temporal, larger than the anterior, curves upward and backward 

 along the side of the head, lying superficial to the temporal fascia, and inosculates 

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

 arteries. The terminal portion of the posterior branch is named the parietal 

 artery (ramus parietalis), 



Applied Anatomy. The temporal artery, as it crosses the zygoma, lies immediately beneath 

 the skin, and its pulsations may be readily felt during the administration of an anesthetic, or 

 under circumstances where the radial pulse is not available; or it may be easily compressed 

 against the bone in order to check bleeding from the temporal region of the scalp. When a flap 

 is raised from this part of the head, as in the operation of trephining, the incision should be 

 shaped like a horseshoe, with its convexity upward, so that the flap shall contain the temporal 

 artery which insures a sufficient supply of blood. The same principle is applied, as far as 

 possible, in making incisions to raise flaps in other parts of the scalp. 



8. The internal maxillary artery (a. maxillaris interna) (Figs. 444 and 445), 

 the larger of the two terminal branches of the external carotid, arises behind the 

 neck of the mandible, and is at first embedded in the substance of the parotid gland ; 

 it passes inward between the ramus of the mandible and the internal lateral liga- 

 ment, and then upon the outer surface of the External pterygoid muscle to the 

 sphenomaxillary fossa to supply the deep structures of the face. For convenience 

 of description it is divided into three portions a maxillary, a pterygoid, and a 

 sphenomaxillary. 



The first or maxillary portion passes horizontally forward and inward, between 

 the ramus of the mandible and the internal lateral ligament, where it lies parallel 



