Coronal transcranial view through central head. Structures anterior to and deep to the clivus are presented in this image. Posterior to the upper and middle clivus is the pons and overlying basilar artery. Laterally, along the lateral surfaces of the body of the sphenoid course the internal carotid arteries. Superiorly, the optic nerves emerge from the optic canals at the apices of the orbits in company with the ophthalmic arteries. Inferiorly, the foramen rotundum and pterygoid canals transmit, respectively, the maxillary nerve and nerve of the pterygoid canals, enroute to the pterygopalatine fossa. The pharyngotympanic tubes leave the middle ear cavity and open anteriorly into the lateral walls of the nasopharynx. Along the lateral aspects of the lower clivus are the openings for the jugular foramen and hypoglossal canal transmitting, respectively, the glossopharyngeal, vagus, spinal accessory, and hypoglossal nerves. (Image courtesy of AL Rhoton, Jr.)