Anterior coronal view of sphenoid, temporal, and occipital bones. In this perspective, the different parts of the sphenoid bone are in view. The lesser wings are separated from the greater wings by the superior orbital fissure. The greater wings present two openings into the pterygopalatine fossa, the foramen rotundum and the pterygoid (Vidian) canal. The body of the sphenoid contains the paired sphenoidal sinuses separated by a septum. The ostia of these sinuses open anteriorly into the sphenoethmoidal recesses. Posteriorly the body presents the sella turcica consisting of the tuberculum sellae anteriorly, the dorsum sellae posteriorly, and the hypophyseal fossa in between. Extending inferiorly are the pterygoid processes, which give rise to lateral and medial pterygoid plates. The pterygoid fissure or notch separates these plates and is filled in by the pyramidal process of the palatine bone. The internal surface of the occipital bone reveals two pairs of depressions or fossae, cerebral and cerebellar, that are separated by the cruciform eminence. The right and left cerebral fossae receive the occipital lobes of the cerebrum and are separated by the groove for the sagittal sinus to which is attached the falx cerebri. The right and left cerebellar fossae receive the cerebellar hemispheres and are separated by the internal occipital crest, to which attaches the falx cerebelli containing the occipital sinus. Right and left cerebral and cerebellar fossae are separated from each other by the transverse groove containing the transverse sinus. At the point of intersection of all four fossae is the internal occipital protuberance. The foramen magnum is the large foramen in the occipital bone and is related laterally with the condylar and hypoglossal canals. The jugular foramen is a space between the occipital bone and petrous part of temporal. (Image courtesy of AL Rhoton, Jr.)