Anterior transsphenoidal coronal view of the middle to lower clivus region. The pharyngotympanic (Eustachian) tubes remain intact in the foreground of this specimen after extensive bone and soft tissue resection and communicate the tympanic cavity with the nasopharynx.  A window in the lower clivus reveals the upper portion of the medulla oblongata and the right and left vertebral arteries. The upper portion of this field shows the posterior wall of the sphenoid sinus (within the body of the sphenoid). Through the thin bony wall the anterior surface of the pituitary gland, as it rests within the sella turcica, is in view. Along the superolateral border of the body of the sphenoid is the apex of the orbit containing the optic nerve, extraocular muscles, and associated neurovasculature to the orbital contents. Inferolaterally are the maxillary nerves passing through the foramen rotundum toward the pterygopalatine fossa. Inferomedial to the foramen rotundum near the floor of the sphenoid sinus are the pterygoid canals transmitting the nerve of the pterygoid canal (Vidian nerve) to the pterygopalatine fossa and pterygopalatine ganglion. (Image courtesy of AL Rhoton, Jr.)