672 THE ARTERIES. 



beneath and to the outside 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 tlu 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 niasseteric artery, Aiys, 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. 



2. Inteknal Maxillary or Gutturo-maxillary Artery (Fig. 381, 27). 



Situated at first immediately within the maxillary condyle, below the articu- 

 lation of the jaw, this artery passes to the inner side, towards the entrance of the 

 subsphenoidal canal, by describing two successive curvatures — the first backwards, 

 the other forwards. After being tnus shaped like an S, it travels forward along 

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

 hiatus, where it is designated the^mlato-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 postei'ior 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, 

 along with the superior maxillary nerve, passes across the space separating the 

 orbital from the maxillary hiatus, by creeping along the palatine bone, beneath a 

 considerable mass of fat. 



Collateral Branches. — The arteries given ofif 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 the pterygoid arteries ; 

 three above, the tympanic, spheno-spinous {great tneningeal), and jwsterior deep 

 temporcd. 



Two escape from the superior portion of the interosseous or sphenoidal 

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

 commence from the third section of the artery : two inferior, the buccal and 

 pcdatine ; and two upper, the superior dental and the nasal. 



1. Inferior Dental Artery (Fig. 381, 28). — This vessel — also named the 

 maxillo-dentcd artery— \^ detached at a right angle from about the middle of 

 the first curvature described by the internal maxillary. It travels forward and 

 downward between the two pterygoid muscles, afterwards between the internal 

 one and the maxillary bone, entering with the inferior maxillary nerve into the 

 dental foramen, through the whole extent of which it passes. Arrived at the 

 mental foramen, it separates into two branches — a deep one, which continues 

 the interosseous course of the vessel, to be distributed to the roots of the tusk or 

 tush, and the three adjoining incisor teeth ; the other superficial, generally very 

 Blender and even capillary, issuing by the mental foramen with the terminal 



