432 ANGIOLOGY. 



ai'tevy enters the pterygoid foramen ; it passes directly upwards, 

 ramifying in the substance of the temporalis muscle, and anas- 

 tomosing with the masseter by a small branch which passes 

 through the sigmoid notch. 



In the pterygoid foramen the internal maxillary artery gives 

 off two branches : — 



Anterior deep temporal. | Ophthalmic. 



The Anterior deep temporal arterj^, given off in the ptery- 

 goid foramen, passes upwards along the anterior border of the 

 temporalis muscle, in which it becomes buried, supplying, in 

 addition, the attolentes and the neighbouring tissues. 



The Ophthalmic artery is a large branch, which leaves the in- 

 ternal maxillary in the pterygoid foramen, near to and sometimes 

 with the last. By the orbital hiatus it gains the lower part of 

 the orbital fossa, forms a circular loop upon itself, and then enters 

 the cranial cavity through the internal orbital foramen, and ter- 

 minates in meningeal and internal lateral nasal branches. The 

 former, after distributing branches to the dura mater and falx 

 cerebri, anastomoses at the base of the crista galli, with its fellow 

 and the anterior cerebral artery. The internal lateral nasal artery 

 passes through the cribriform plate of the ethmoid bone, enters the 

 nasal chamber, and is distributed over the ethmoidal volutes and 

 septum nasi. The ophthalmic gives off muscular branches to the 

 muscles of the eye ; the ciliary arteries, which go to the eye- 

 ball, and are chiefly distributed to the choroid coat, ciliary pro- 

 cesses and iris ; the aHeria centralis retince, which passes through 

 the axis of the optic nerve ; the supraorbital artery, which 

 passes up the internal wall of the orbital fossa in company with 

 the vein and nerve, and through the supraorbital foramen, to 

 be distributed to the skin of the forehead and muscles of the 

 frontal region ; the lachrymal artery, which runs between the 

 muscles and upper wall of the fossa, and terminates in the lach- 

 rymal gland and upper eyelid; finally, cranial branchlets, which 

 are distributed over the anterior lobe of the cerebrum, anasto- 

 mosing with the anterior cerebral artery. 



The branches given off by the internal maxillary artery, after 

 leaving the pterygoid foramen, are : — 



Buccal. I Supei'ior dental. 



Staphyline. | Spheno-palatine. 



