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NEUROLOGY 





Internal carotid, artery 

 Cavernous sinus 



other in the cavernous sinus, at the superior orbital fissure, and in the cavity of 

 the orbit, as follows: 



In the cavernous sinus (Fig. 786), the oculomotor, trochlear, and ophthalmic 

 nerves are placed in the lateral wall of the sinus, in the order given, from above 

 downward. The abducent nerve lies at the lateral side of the internal carotid 

 artery. As these nerves pass forward to the superior orbital fissure, the oculo- 

 motor and . ophthalmic divide into 

 branches, and the abducent nerve 

 approaches the others; so that their 

 relative positions are considerably 

 changed. 



In the superior orbital fissure (Fig. 

 787), the trochlear nerve and the 

 frontal and lacrimal divisions of the 

 ophthalmic lie in this order from 

 the medial to the lateral side upon 

 the same plane; they enter the cavity 

 of the orbit above the muscles. The 

 remaining nerves enter the orbit be- 

 tween the two heads of the Rectus 

 lateralis. The superior division of 



the oculomotor is the highest of these; beneath this lies the nasociliary branch 

 of the ophthalmic; then the inferior division of the oculomotor; and the abducent 

 lowest of all. 



OcuLomotor 



Trochlear nerve- 

 Ophthalmic nerve 



Abducent nerve 



Maxillary nerve 



FIQ. 786. Oblique section through the right cavernous 

 sinus. 



Frontal nerve 

 ramus of oculomotor nerve 

 Sup. orbital fissure 

 Lacrimal nerve 



Levator palpebrcs 

 I Nasociliary nerve 

 I Trochlear nerve 

 TrocTilea 



Abducent nerve 



Inf. ramus of oculomotor Inf. orbital Optic foramen 



nerve fissure 



FIG. 787. Dissection showing origins of right ocular muscles, and nerves entering by the superior orbital fissure. 



In the orbit, the trochlear, frontal, and lacrimal nerves lie immediately beneath 

 the periosteum, the trochlear nerve resting on the Obliquus superior, the frontal 

 on the Levator palpebree superioris, and the lacrimal on the Rectus lateralis. 

 The superior division of the oculomotor nerve lies immediately beneath the Rectus 



