THE HEAD AND NECK 1179 



nerve. Its relation to the levator labii superioris is variable. It 

 may be under cover of, or over, that muscle. Deep. — ^The body of 

 the inferior maxilla (where pulsation can readily be felt in the 

 vessel), the buccinator, the levator anguli oris, and the infra- 

 orbital nerve. External. — ^The facial vein, which is at a little 

 distance from it, except at the body and base of the mandible, 

 where the vein lies close to the outer side of the vessel. 



Facial Branches. — (i) Muscular branches, of small size, arise from 

 the outer side of the vessel, and are distributed to the structures in the 

 masseteric, buccal, and infra-orbital regions, where they anastomose 

 with the buccal, transverse facial, and infra-orbital arteries. (2) The 

 inferior labial artery passes forwards over the body of the mandible, 

 and beneath the depressor anguli oris, to supply the structures 

 between the lower lip and the base of the mandible. It anasto- 

 moses with the inferior coronary, mental, and submental arteries. 

 (3) The inferior coronary artery arises just below the angle of the 

 mouth, and passes inwards beneath the depressor anguli oris. In 

 the lower lip it lies near the margin, between the orbicularis oris 

 and the mucous membrane, and it anastomoses with its fellow 

 of the opposite side, and with the inferior labial. (4) The superior 

 coronary artery, of larger size than the inferior, arises just above 

 the angle of the mouth, under cover of the zygomaticus major. Its 

 position in the upper lip is similar to that of the inferior coronary 

 in the lower lip, and it anastomoses with its fellow of the opposite 

 side. Near the middle line it furnishes the artery of the septum nasi, 

 which ramifies on the columella nasi as far as the tip of the nose. 

 The superior and inferior coronary arteries of each side sometimes 

 arise together. The vessels of each side, superior and inferior, 

 form in each lip a tortuous arterial arch, which is necessarily 

 divided in operations upon one or other lip. (5) The lateral nasal 

 arteries arise opposite the nose, upon the side of which they ramify. 

 They anastomose with the nasal branch of the ophthalmic, the 

 artery of the septum, the terminal branch of the anterior ethmoidal 

 artery, and its fellow of the opposite side. (6) The angular artery 

 is the terminal branch of the facial at the inner canthus of the eye. 

 It lies either beneath, or embedded in, the levator labii superioris 

 alaeque nasi, and supplies the side of the root of the nose and the 

 adjacent part of the orbicularis palpebrarum. It anastomoses with 

 the nasal branch of the ophthalmic artery. 



The facial vein commences above the inner canthus of the eye 

 in the angular vein, which is formed by the union of the frontal 

 and supra-orbital veins. The course of the vessel is downwards 

 and outwards, external to the artery and at a little distance from 

 it, except over the body and base of the inferior maxilla, where 

 it lies close to its outer side and in contact with the anterior 

 border of the masseter. The vein is much less tortuous than the 

 artery, and in the lower part of its course descends almost 

 vertically. The cervical part of the vein, which terminates in 

 the internal jugular, has been already described. The muscular 



