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OPHTHALMIC ARTERY. 



The Cavernous portion is situated in the inner wall of the cavernous 

 sinus, and is in relation by its outer side with the lining membrane of the 

 sinus, the sixth nerve, and the ascending branches of the carotid plexus. 

 The third, fourth, and ophthalmic nerves are placed in the outer wall of 

 the cavernous sinus, and are separated from the artery by the lining mem- 

 brane of the sinus. 



The Cerebral portion of the artery is enclosed in a sheath of the arach 

 noid, and is in relation with the optic nerve. At its point of division it i 

 situated in the fissure of Sylvius. 



Branches. The cervical portion of the internal carotid gives off no 

 branches : from the other portions are derived the following : 



Tympanic, 

 Anterior meningeal, 

 Ophthalmic, 

 Anterior cerebral, 

 , Middle cerebral, 

 Posterior communicating, 

 Choroidean. 



The Tympanic is a small branch which enters the tympanum through a 

 minute foramen in the carotid canal. 



The interior meningeal is distributed to the dura mater and Casserian 

 ganglion. 



The Ophthalmic artery arises from the cerebral portion of the internal 

 carotid, and enters the orbit through the foramen opticum, immediately to 

 the outer side of the optic nerve. It then crosses the optic nerve to the 

 inner wall of the orbit, and runs along the lower border of the superior 

 oblique muscle, to the inner angle of the eye, where it divides into two 

 terminal branches, the frontal and nasal. 



Branches. The branches of the ophthalmic artery may be arranged into 

 two groups : first, those distributed to the orbit and surrounding parts ; 

 and, secondly, those which supply the muscles and globe of the eye. 

 They are 



First Group. Second Group. 



Lachrymal, Muscular, 



Supra-orbital, Anterior ciliary, 



Posterior ethmoidal, Ciliary short and long, 



Anterior ethmoidal, Centralis retina;. 



Palpebral, 



Frontal, 



Nasal. 



The Lachrymal is the first branch of the ophthalmic artery, and is usu 

 ally given off immediately before that artery enters the optic foramen. It 

 follows the course of the lachrymal nerve, along the upper border of the 

 external rectus muscle, and is distributed to the lachrymal gland. The 

 small branches which escape from the gland supply the conjunctiva ami 

 upper eyelid. The lachrymal artery gives off a malar branch which passes 

 through the malar bone into the temporal fossa and inosculates with the 

 deep temporal arteries, while some of its branches become subcutaneous 

 on the cheek, and anastomose with the transverse facial. 



