(I) Frontal bone (with frontal sinus); (II) Crista galli (of ethmoidal bone); (III) Perpendicular lamina of the ethmoid bone; (IV) Body of the ethmoid bone; (V) Back of the sella turcica (posterior clinoid process); (VI) Sella turcica; (VII) Sphenoid sinus; (VIII) Basilar part of the occipital bone (with the fossa for medulla oblongata); (IX) Occipital part of the occipital bone; (X) Vomer; (XI) Pharynx; (XII) Tentorium cerebelli (with confluence of sinuses and opened great cerebral vein of Galen).