4. The body one bone The greater wing two bones The lesser wing two bone Lateral platetwo bone medial pterygoid plate two bone

5. The body a median raised part in the middle cranial fossa

6. anteriorly with the cribriform plate of the ethmoid bone, the lateral aspect articulates with the labyrinth of the ethmoid bone above and with the orbital process of the palatine bone below. The inferior aspect articulates with the nasal septum in the midline the ethmoid anteriorly and the vomer inferiorly and also with the sphenoidal process of the palatine bone. Posteriorly it is fused to the basilar part of the occipital bone, just posterior to the vomer.

7. the tuberculum sellae an elevation Posterior to the sulcus,

8. the sulcus chiasmatis, which is related to the optic chiasma the optic canal transmits the optic nerve and ophthalmic artery.

9. sella turcica a deep depression behind the elevation at the superior surface the central portion of this is the hypophysial fossa, which lodges the Pituitary gland (hypophysis cerebri).

10. the dorsum sellae square plate of bone posterior to the sella turcica.

11. the posterior clinoid processes two tubercles at the superior angles of the dorsum sellae give attachment to the fixed margin of the tentorium cerebelli

12. cavernous sinus lateral wall the 3rd and 4th cranial nerves and the ophthalmic and maxillary division the 5th cranial nerve. The internal carotid artery and the 6th cranial nerve pass forward through the sinus.

13. The sphenoid air sinuses The spheno-ethmoidal recess above the superior conchae and anterior to the body.

14. The inferior surface formed the roof of the posterior part of the nasal cavity.

15. The anterior aspect of the body in the midline has the sphenoidal crest On each side of the crest this surface of the body formed the posterior wall of the spheno-ethmoidal recess.

16. The greater wing rectangular in shape with its long axis running anteriolateraly, parallel to the lateral Wall of the orbit.

17. The posteromedial angle is truncated and attached to the lowest part of the lateral surface of the body of the sphenoid well below the level of the lesser wing.

18. The posteriolateral angle projects backwards and has the spine of the sphenoid extending downwards from it immediately posterior to the foramen spinosum.

19. The anterior part of the rectangle is bent upwards the internal surface form a concave cerebral surface the external surface form the posterior part of the lateral wall of the orbital cavity and part of the medial wall of the temporal fossa

20. articulates superiorly with the lesser wing and the inferior surface of the frontal and parietal bones

21. The infratemporal crest The temporal infratemporal fossa

22. The inferior orbital fissure It leads forward into the orbit. a horizontal fissure between the greater wing and the maxilla.

23. the lateral wall the floor of the medial cranial fossa

24. foramen rotundum behind the medial end of the superior orbital fissure communicates the medial crania fossa to the pterygopalatine fossa the maxillary nerve division of 5th cranial nerve from the trigeminal ganglia.

25. foramen ovale the upper part of the medial wall of the nasal cavity communicates the medial crania fossa to the infratemporal fossa the large sensory root and small motor root of the mandibular nerve division of the 5th cranial nerve the lesser petrosal nerve

26. foramen spinosum communicates the medial cranial fossa to the infratemporal fossa the middle meningeal artery The artery then runs forward and laterally in a groove between the greater wing and the upper surface of the squamous part of the temporal bone behind the spine of sphenoid bone.

27. foramen lacerum: large and irregular shaped the sphenoid bone and the apex of the petrous part of the temporal bone The inferior opening of the foramen in life filled by cartilage and fibrous tissue communicates the middle cranial cavity to the neck small blood vessels

28. Immediately behind each medial pterygoid plate, there is a groove between the greater wing of the sphenoid bone and the petrous part of the temporal bone behind the spine of sphenoid bone, these groove for cartilaginous part of the auditory tube and can see the external auditory meatus

29. The lesser wing Project laterally from the anterosuperior part of the body

30. The upper surface the posterior limit of the anterior cranial fossa and ends medially in an anterior clinoid process immediately lateral to the optic canal, gives attachment to the tentorium cerebelli

31. The lower surface forms the most posterior part of the roof of the orbit The sharp posterior margin of the lesser wing formed the anterior border of the middle cranial fossa.

32. the superior orbital fissure the middle cranial fossa and the orbit the lacrimal, frontal, trochlear, oculomotor, nasociliary, and abducent nerves with the superior ophthalmic vein.

33. the optic canal the optic nerve and ophthalmic artery, a branch of the internal carotid artery

34. The sphenoparietal venous sinus runs medially along the posterior border of the lesser wing and drain into the cavernous sinus.

35. Lateral and medial pterygoid plates These plates fuse in their upper parts anteriorly but inferiorly they diverge

36. The medial pterygoid plate the posterior part of the lateral wall of the nasal cavity

37. The pterygomaxillary fissure the pterygoid process of the sphenoid bone and the back of maxilla

38. superiorly where a notch in the upper margin of the medial pterygoid plate forms the sphenoplatine foramen with in the sphenoid bone.

39. The pterygoid hamulus The inferior end of the medial pterygoid plate is prolonged as a curved spike of bone

40. Between the infratemporal crest and the lateral pterygoid plate is the infratemporal fossa.