INTERNAL MAXILLARY ARTERY. 



289 



Fig. 147.' 



the two heads of the external t 

 and enters the ptery go-maxillary fossa. 

 Occasionally it passes between the two 

 pterygoid muscles, without appearing on \1 

 the outer surface of the external ptery- A 

 gold. In consideration of its course, 

 this artery may be divided into three 

 portions; maxillary, pterygoid, and 

 spheno-maxillary. 



Relations. The maxillary portion is 

 situated between the ramus of the jaw 

 and the internal lateral ligament, lying 

 parallel with the auricular nerve ; the 

 pterygoid portion between the external 

 pterygoid muscle, and the masseter and 

 temporal muscle. The pterygo-maxillary portion lies between the two 

 heads of the external pterygoid muscle, and, in the spheno-maxillary fossa, 

 is in relation with Meckel's ganglion. 



Branches. 

 Maxillary Portion. 



Tympanic, 



Inferior dental, 



Arteria meningea media, 



Arteria meningea parva. 



Pterygoid Portion. 

 Deep temporal branches, 

 External pterygoid, 

 Internal pterygoid, 

 Masseteric, 

 Buccal. 



Ptery go-maxillary Portion. 

 Superior dental, 

 Infra-orbital, 

 Pterygo-palatine, 

 Spheno-palatine, 

 Posterior palatine, 

 Vidian. 



The Tympanic branch is small, and not likely to be seen in an ordinary 

 dissection; it is distributed to the temporo-maxillary articulation and 

 meatus, and passes into the tympanum through the fissura Glaseri. 



The Inferior dental descends to the dental foramen, and enters the 

 canal of the lower jaw in company with the dental nerve. Opposite the 

 bicuspid teeth it divides into two branches, one of which is continued on- 

 wards within the bone as far as the symphisis, to supply the incisor teeth, 



* 1. The external carotid artery. 2. The trunk of the transverse facial artery. 3, 4. 

 The two terminal branches of the external carotid. 3. The temporal artery; and 4. 

 The internal maxillary, the first or maxillary portion of its course; the limit of this por- 

 tion is marked by an arrow. 5. The second, or pterygoid portion, of the artery; tne 

 limits are bounded by the arrows. 6. The third or pterygo-maxillary portion. The 

 branches of the maxillary portion are, 7. A tympanic branch. 8. The arteria meningea 

 magna. 9. The arteria meningea parva. 10. The inferior dental artery. The branches 

 of the second portion are wholly muscular, the ascending ones being distributed to tft* 

 temporal, and the descending to the four other muscles of the inter-maxillary region, 

 viz. the two pterygoids, the masseter and buccinator. The branches of the pterygo 

 maxillary portion of the artery are, ] 1. The superior dental artery. 12. The infra-or- 

 bital artery. 13. The posterior palatine. 14. The spheno-palatine or nasal. 15. Tha 

 ptery go-palatine. 1G. The Vidian. * The remarkable bend which the third portion 

 of the artery makes as it turns inwards to enter the pterygo-inaxillary fossa. 



25 T 



