Relation of orbital structures to brain stem and cranial nerves II-V
The brain has been removed except for the brain stem, optic chiasm and optic tracts. The tentorium has been cut away and the cavernous sinus opened to show the course of cranial nerves related to the orbit with the exception of the abducens nerve which remains almost completely covered.
Olfactory tract right (cut off at attachment to olfactory trigone)
Optic chiasm and internal carotid artery (cut off)
Upper pointer: Optic nerve (II) Lower pointer: Anterior clinoid process (attachment of tentorium visible)
Superior rectus muscle
Lacrimal artery
Lateral rectus muscle
Ophthalmic nerve (V1)
Maxillary nerve (V2)
Sphenoid sinus
Internal maxillary artery
Pterygoid process sphenoid bone (partially resected)
Internal pterygoid muscle
Buccinator muscle
Posterior clinoid process
Base of peduncle (cut across)
Upper pointer: Lateral geniculate body Lower pointer: Optic tract
Oculomotor nerve (III)
Trochlear nerve (IV)
Tentorial nerve (recurrent meningeal branch of ophthalmic nerve, which in this specimen grossly appears to be a branch of the trochlear nerve; the tentorium has been cut away from the nerve)