Endoscopic transnasal view of right anterior aspect of pituitary gland. The clivus and body of sphenoid have been removed to show the sellar and parasellar regions. The middle of the lower part of the image shows the basilar artery overlying the pons and the basilar venous plexus. The pituitary gland is reflected medially to show the inferior hypophyseal ligament connecting its capsule to the medial wall of the cavernous sinus, which contains the cavernous segment of the internal carotid artery (ICA). Superiorly, the intercavernous sinus courses within the diaphragma sellae. The meningohypophyseal trunk is shown arising from the cavernous segment and it supplies the posterior pituitary and meninges overlying the clivus and tentorium. The superior hypophyseal artery, a branch off the supraclinoid segment of ICA, is seen at the top left of the image and supplies the optic nerve and chiasm and the pituitary stalk and gland. (Image courtesy of AL Rhoton, Jr.)