THE COMMON CAROTID ARTERIES 585 



origin of the pyramidal muscle of the nose, (supermaxillo-nasalis magnus), 

 and sometimes below that muscle. It subsequently gains the upper lip, 

 along with the infra- orbital branches of the superior maxillary nerve, 

 by passing between the supernasalis-labialis and the pyramidal muscle of 

 the nose ; it then terminates in forming an arch by inosculation with the 

 palato-labialis artery. 



The branches it gives off pass to the external ala of the nose and the 

 textures of the upper lip. Some are expended in the muscles just named, 

 and in the alveolo-labialis. 



2. Maxillo-mwscular Artery. (Fig. 286, 21.) 



The maxillo-muscular artery is a vessel that does not appear to have its 

 representative in Man. It emerges from the external carotid, above the 

 point whero it is included between the large branch of the os hyoides and 

 the stylo-hyoid muscle. Remarkable for the very obtuse angle it forms at 

 its origin with the principal vessel, it descends behind the posterior border 

 of the inferior maxiUa, covered by the parotid gland. It then divides 

 into two branches : a deep one, which goes to the internal pterygoid muscle, 

 after furnishing some ramuscules to the neighbouring organs ; and a 

 superficial one, which turns round the posterior border of the maxilla, 

 and emerging from beneath the parotid gland, above the insertion of 

 the sterno-maxillaris muscle, plunges into the masseter, and expends itself 

 in the body of that muscle by several branches which anastomose with the 

 divisions of the subzygomatic artery. 



3. Posterior Auricular Artery. (Fig. 286, 22.) 



Third collateral branch of the external carotid, the posterior auricular 

 artery arises at a very acute angle above, and a little behind, the preceding 

 vessel. It ascends beneath the parotid gland, behind the base of the concha 

 of the ear, crosses the cervico-auricular muscles, and reaches the extremity 

 of the cartilage by passing underneath the skin which covers its posterior 

 plane. 



In its course, it emits several ascending auricular branches, which arise 

 at different elevations and cover the concha with their divisions. Among 

 these we ought to distinguish the first (Fig. 286, 23) ; this has its origin at 

 the temporal trunk, and soon divides into two branches : one, profound, 

 after sending a very thin filament into the middle ear by the stylo-mastoid 

 foramen, passes between the external auditory canal and the mastoid 

 process to enter the subconchal adipose tissue and the internal scuto- 

 auricular muscle ; the other, superficial, imbedded in the parotid tissue, 

 proceeds to the external side of the concha, and buries itself in the interior 

 of that cartilage, along with the middle auricular nerve, after abandoning 

 some external ramuscules. 



.Trom these auricular branches there also escape a multitude of 

 parotideal twigs. 



4. Superficial Temporal Artery or Temporal Trunk. (Fig. 286, 25.) 

 -This is the smallest of the two terminal branches of the external carotid. 

 After a short ascending course between the parotid gland, the guttural pouch, 

 and the neck of the maxillary condyle, behind which it is situated, 

 this artery is divided into two branches : the anterior auricular and the 

 ivhzygomatie. 



