THE CRANIAL REGION. 15 



thus forming a free inosculation between the internal and 

 external carotid arteries. Behind, the occipital and the 

 posterior auricular branches of the external carotid artery 

 freely anastomose with each other, and with the above- 

 mentioned vessels. 



The superficial temporal artery, which is easily seen 

 beneath the skin in its tortuous course, is liable to injury, 

 which, in the event of the main trunk being divided, 

 either entirely or partially, may be serious by the forma- 

 tion of a false aneurism from the escape of blood beneath 

 the tissues. In such a case the tumor must be opened 

 and the clot turned out, and both ends of the bleeding 

 vessel tied. If the operation of arteriotomy be" required, 

 the anterior branch of this vessel is the one selected, just 

 at the spot where it begins to be covered by the hairy 

 scalp. In performing this operation a small puncture 

 only is necessary, and when complete the vessel should 

 be entirely divided, so that by the retraction of the cut 

 ends the formation of a false aneurism may be prevented. 

 In such plastic operations as the restoration of the upper 

 eyelid, or of rhinoplasty, the preservation of the supra- 

 orbital arteries is of great importance for the proper 

 nourishment of the flap. 



Veins. The arteries are generally accompanied by 

 small veins ; one vessel in particular, the vena prceparata, 

 which is situated in the middle of the forehead, and is 

 plainly visible during bodily exertion or under excite- 

 ment, is worthy of note. This vein has been proposed 

 as suitable for venesection. 



The nerves supplying the muscles and integument, are 

 in front, the supra-orbital and supra-trochlear branches 

 of the frontal, and some few inosculating branches of the 

 facial. These nerves are frequently the seat of neuralgia, 



