Anterior coronal view of sphenoid, temporal, parietal, 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. Extending inferiorly are the pterygoid processes, which give rise to lateral and medial pterygoid plates. The coronal suture unites the frontal bone with the parietal bones. The parietal bones fuse in the midline at the sagittal suture and to the squamous part of the temporal bone by the squamosal sutures. The lambdoid suture unites the occipital bone with the parietal bones. The internal surface of the occipital bone reveals two pairs of fossae, cerebral and cerebellar. The right and left cerebral fossae are separated by the groove for the sagittal sinus to which is attached the falx cerebri. The right and left cerebellar fossae are separated by the internal occipital crest, to which attach 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. (Image courtesy of AL Rhoton, Jr.)