Endoscopic transnasal view of anterior inferior aspect of pituitary gland. The clivus and body of sphenoid have been largely removed to show the sellar and parasellar regions. The lower left part of the image shows the basilar artery overlying the pons. The pituitary gland (its neurophysis and adenohypophysis parts) can be seen. The meningohypophyseal trunk is shown arising from the cavernous segment and it supplies the posterior pituitary and meninges overlying the clivus and tentorium. The ophthalmic artery, a branch off the supraclinoid segment of the internal carotid artery, is seen at the top left of the image with the optic nerve. It passes with the nerve into the optic canal and supplies the orbital contents. The carotid sympathetic nerve plexus courses along the surface of the internal carotid artery and the ophthalmic nerve can be seen along the lateral aspect of the artery along the upper wall of the cavernous sinus. (Image courtesy of AL Rhoton, Jr.)