Endoscopic view of the sella turcica. The clivus has been drilled to reveal the basilar artery posteriorly. Pontine branches are seen radiating laterally from it. The pituitary gland is enclosed by the dura of the sella turcica containing the intercavernous sinuses: anterior, inferior, and posterior. Lateral to the pituitary and body of the sphenoid are the cavernous sinuses containing the cavernous segments of the internal carotid arteries which are surrounded by the carotid sympathetic plexus providing sympathetic innervation to the head. Laterally, the abducens nerve is visible as it ascends within the prepontine cistern before entering the cavernous sinus. The basilar sinus is visible in the dura overlying the upper clivus.  (Image courtesy of AL Rhoton, Jr.)