OF THE EXTERIOR OF THE HEAD. 



651 



The frontal vein commences on the anterior part of the skull by a venous 

 plexus which communicates with the anterior tributaries of the temporal vein. 

 The veins converge to form a single trunk, which runs downward near the 

 middle line of the forehead parallel with the vein of the opposite side, and unites 

 with it at the root of the nose by a transverse branch called the nasal arch. 

 Occasionally the frontal veins join to form a single trunk, which bifurcates at the 



FrontaL 



'ommunicatiiig 

 branch uith 

 hthalmic rein. 

 Angular. 



\ Superior thyroid. 



FIG. 38L-Veins of the head and neck. 



root of the nose into the two angular veins. At the root of the nose the veins 

 diverge and join the supra-orbital vein, at the inner angle of the orbit, to form 

 the angular vein. 



The supra-orbital vein commences on the forehead, communicating with the 

 anterior temporal vein, and runs downward and inward, superficial to the 

 Occipito-frontalis muscle, receiving tributaries from the neighboring structures, 

 and joins the frontal vein at the inner angle of the orbit to form the angular 

 vein. 



The angular vein, formed by the junction of the frontal and supra-orbital 

 veins, runs obliquely downward and outward on the side of the root of the nose, 

 and receives the veins of the ala nasi on its inner side and the superior palpebral 

 veins on its outer side ; it moreover communicates with the ophthalmic vein, thus 



