Endoscopic view of left anterior lateral portion of the pons and prepontine cistern. Removal of clival bone exposes portions of clival dura mater and underlying arachnoid mater. Deep to this is the pons, with the prepontine cistern  intervening. Pontine arteries and the superior cerebellar artery are branches of the basilar artery (not shown in image). The abducens (CNVI) nerve is seen emerging from the pons, coursing through the prepontine cistern, before traversing the arachnoid and dura enroute to the cavernous sinus. The dorsal meningeal artery, a branch of the meningohypophyseal trunk that arises from the cavernous segment of the internal carotid artery, enters the dura of the posterior cavernous sinus wall and supplies the clival dura and sixth cranial nerve. (Image courtesy of AL Rhoton, Jr.)