OPHTHALMIC ARTERY. 

 Fig. 260. , 



361 



Fig. 260. SEMIDIAGRAMMATIC VIEW OP THE ARTERIES OP THE ORBIT AND NEIGHBOUR- 

 ING PARTS, WITH THEIR BRANCHES AND ANASTOMOSES (founded on Hirschfeld and 

 Leveille, with additions). 



The outer wall of the orbit has been removed, the sinus maxillaris is laid open, the 

 eyelids are turned forwards, and the external and superior recti, and the superior oblique 

 muscles have been partially removed, a, optic nerve ; b, hook, holding up the posterior 

 part of the superior rectus muscle, the anterior part of which is left attached to the eye- 

 ball ; c, lachrymal gland, thrown up on the frontal bone ; d, insertion of the inferior 

 oblique muscle ; e, inferior rectus ; /, /, anterior and posterior portions of the divided 

 external rectus ; g, maxillary sinus ; h, hook, holding up the eyelids, of which the deep 

 surface is exhibited. 



I, internal carotid artery below the inferior aperture of the carotid canal of the temporal 

 bone, which is indicated higher up by a ring surrounding the artery ; I', the part of the 

 artery situated within the temporal bone, a second ring indicating the place of the upper 

 aperture of the temporal canal ; I", the part of the artery situated on the sphenoid bone ; 

 upon this artery, 1, twig to the mastoid cells and tympanum ; 2, twigs in the cavernous 

 sinus ; 3, communicating to the posterior cerebral ; 4, middle cerebral ; 5, anterior 

 cerebral. 



II, basilar artery ; upon this artery, 6, posterior cerebral ; 7, superior cerebellar : the 

 accented numbers, 3', 4', 5', 6', 7', indicate, on the left side, the arteries already named 

 under the same numbers on the right side, and with these and the anterior communicating 

 branch marked by +, complete the Circle of Willis. 



III, upper part of the external carotid artery dividing into III x , the superficial temporal, 

 and III', III", the internal maxillary artery ; upon the latter artery, 1, inferior dental 

 branch ; 2, middle meningeal ; 3, 3, masseteric and pterygoid branches; 4, buccal ; 5, 5, 

 anterior and posterior deep temporal ; 6, posterior superior dental ; 7, infraorbital ; 7', 

 branches of the same issuing upon the face ; 8, part of the internal maxillary, which 

 turns into the spheno-maxillary fossa. 



IV, facial artery, terminating at 11, in the angular, and giving off, at 12, the lateral 

 nasal branches, and others which communicate with the infraorbital. 



In the orbit the following numbers indicate the ophthalmic artery and its branches : 1, 

 the ophthalmic artery at its origin from the internal carotid ; 1', the same artery con- 

 tinued on the upper and inner side of the orbit ; 2, lachrymal branch ; 3, central artery of 

 the retina ; 4, some of the ciliary arteries ; 5, 5, upper and lower muscular branches ; 

 6, supraorbital ; 7, 7', posterior and anterior ethmoidal arteries ; 8, palpebral ; 8', 8", 

 its superior and inferior divisions ; 9, frontal; 10, nasal communicating with the angular 

 of the facial. 



B B 



