586 THE ARTERIES. 



ANTERIOR AURICULAR ARTERY (Fig. 286, 26). This vessel appears to 

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

 temporal trunk. Embraced, near its origin, by the facial nerve and sub- 

 zygomatic branch of the inferior maxillary nerve, it rises behind the 

 temporo-maxillary articulation and supercondyloid 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. 286, 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, beneath, and to the %utside of, the afore-mentioned 

 condyle. There it ends in two branches of equal volume : a superior or 

 superficial, and an inferior or deep, both of which ramify in the substance 

 of the masseter muscle, and anastomose with the divisions of the maxillo- 

 muscular, or with the masseter branches of the external maxillary arteries. 



The superior branch, or transverse artery of the face, goes towards the 

 anterior border of the masseter muscle in a flexuous manner, close to 

 the zygomatic ridge. At first lying on the superficies of the masseter, 

 it afterwards buries itself in that muscle. 



The inferior branch, or masseteric artery, dips in among the deep 

 fasciculi of the masseter muscle, to which it is distributed, along with 

 the masseteric nerve. Near its origin, it communicates with the deep 

 posterior temporal artery by a fine ramuscule, which passes into the sigmoid 

 notch. In Man and some animals, this artery comes from the internal 

 maxillary. 



5. Internal maxillary or Gutturo-maxillary Artery. (Fig. 286, 27.) 



Situated at first immediately within the maxillary condyle, below the 

 articulation of the jaw, this artery passes to the inner side, towards the 

 entrance of the subsphenoidal (or pterygo-palatine) canal, by describing 

 two successive curvatures : the first backwards, the other forwards. After 

 being thus shaped like an S, it travels forward along the subsphenoidal 

 canal to the orbital hiatus, and then reaches the maxillary hiatus to enter 

 the palatine canal, where it is designated the palato-labial artery. 



In order to study its relations, the course of this artery may be divided 

 into three portions : a posterior or guttural, a middle or sphenoidal, and an 

 anterior or infra-orbital. The posterior portion lies on the internal face of 

 the external pterygoid muscle, covered inwardly by the guttural pouch, and 

 crossed outwardly by the inferior maxillary nerve and some of its branches. 

 The middle division is enveloped by the bony walls of the subsphenoidal 

 canal. The anterior portion, alone with the superior maxillary nerve, 

 passes across the space separating the orbital from the maxillary hiatus, by 

 creeping along the palate bone, beneath a considerable mass of fat. 



COLLATERAL BRANCHES. The arteries given off by the internal maxillary 

 on its course are eleven principal. Five arise from the first portion of the 

 vessel : two below, the inferior dental and the group of pterygoid arteries ; 

 three above, the tympanic, spheno-spinous, and deep posterior temporal. 



Two escape from the superior portion of the interosseous or sphenoidal 

 division. These are the deep anterior temporal and ophthalmic arteries. Four 



