TEE COMMON CAROTID ARTERIES. 671 



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

 where it is included between the large cornu of the os hyoides and the 

 stylo-hyoideus 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 maxilla, 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. 381, 22). 



Third colhateral branch of the external carotid, the posterior auricular artery 

 arises at a very acute angle above, and a little behind, the ])receding 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. 381, 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, 

 embedded 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. 



From these auricular branches there also escape a multitude of parotideal twigs. 



Terminal Branches of the External Carotid. 



1. Superficial Temporal Artery or Temporal Trunk (Fig. 381, 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 subzt/gomatic. 



Anterior Auricular Artery (Fig. 3H1, 2G). — This vessel appears to be, 

 not only by its volume, but also by its direction, the continuation of the temporal 

 artery. Embraced, near its origin, by the facial nerve and subzygomatic branch 

 of the inferior maxillary nerve, it rises behind the temporo-maxillary articulation 

 and supra-condyloid process, beneath the parotid gland, to the temporal muscle, 

 into which it passes after emitting parotideal twigs and auricular branches, one 

 of which penetrates to the interior of the concha, while the others are expended 

 in the anterior muscles of the ear and the integuments covering these muscles. 



Subzygomatic Artery (Fig. 381, 25). — More considerable than the anterior 

 auricular, this artery disengages itself from beneath the parotid gland by turning 

 round the posterior border of the maxilla, along with the nervous anastomosis 

 which gives rise to the subzygomatic plexus, and is placed above that anastomosis, 



