26 TOPOGRAPHIC AND APPLIED ANATOMY. 



PLATE 2. 



The external muscles, arteries, veins, and nerves of the face. 



scalp is supplied with blood from all sides, and the practical application is that even very large 

 cutaneous flaps with small pedicles will readily heal when replaced in their proper position. 

 The arteries also give off numerous branches to the cranium. 



The arteries of the scalp (see Plate 2) originate partly from the internal, but chiefly from 

 the external carotid. The temporal and occipital branches are so large that in rare instances they 

 have been known to produce a fatal hemorrhage. 



The branches of the external carotid artery are : 



1. The superficial temporal, the direct upward continuation of the external carotid. It 

 passes upward covered by the parotid gland behind the ramus of the jaw, runs over the zygoma, 

 and, at a varying distance (usually about one centimeter) above the zygoma, divides into an 

 anterior or frontal branch and a posterior or parietal branch. The other main branches, varying 

 somewhat in their point of origin, are the transverse facial (passing forward beneath the zygoma 

 and upon the masseter muscle) and a smaller artery, the orbital (running above the zygoma to the 

 external canthus of the eye). The pulsation of the temporal artery may be palpated in front of 

 the tragus, where the vessel leaves the parotid gland, and where it may be ligated. 



2. The occipital artery, one of the two posterior branches of the external carotid, passes 

 backward beneath the posterior belly of the digastric muscle, grooves the mastoid portion of the 

 temporal bone behind the mastoid process (this groove is frequently absent), ascends between 

 the muscles of the neck, pierces the fibrous origin of the trapezius to one side of the median line 

 [at junction inner and middle thirds of superior curved line. ED.], and runs upward upon the 

 occipitofrontalis muscle. It has no large branches bearing special names which are distributed 

 to the scalp. If the mastoid and parietal foramina are well developed, this artery gives off a 

 mastoid and a meningeal branch which run through these foramina and supply the dura mater. 



3. The posterior auricular artery, the other and smaller of the two posterior branches of the 

 external carotid, runs upward in front of the mastoid process behind the ear and is covered by the 

 posterior auricular muscle. 



The branches furnished by the internal carotid come out of the orbit from the ophthalmic 

 artery. They are small vessels which possess additional interest from their anastomoses with 

 the branches of the external carotid. They are: 



1. The frontal artery, passing upward through the frontal notch alongside of the root of the 

 nose. 



2. The supraorbital artery, external to the preceding vessel, which runs through the supra- 

 orbital notch or foramen to reach the skin of the forehead. 



Veins. Only the larger venous trunks accompany their corresponding arteries; the remain- 

 ing venous branches form a large-meshed network upon the galea aponeurotica. They acquire 

 special importance from their connection with the interior of the cranial cavity through the 

 emissary foramina and from the fact that they receive numerous tributaries from the cranium. 

 We observe: 



i. The frontal vein, frequently single (the "vein of anger"), which is found in the frontal 



