The body one boneThe greater wing two bonesThe lesser wing two bone Lateral plate two bone medial pterygoid plate two bone

The body

a median raised part in the middle cranial fossa

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.

the tuberculum sellae

an elevation Posterior to the sulcus,

the sulcus chiasmatis, which is related to the optic chiasma

the optic canal transmits the optic nerve and ophthalmic artery.

sella turcicaa 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).

the dorsum sellae

square plate of bone posterior to the sella turcica.

the posterior clinoid processes

two tubercles at the superior angles of the dorsum sellae

give attachment to the fixed margin of the tentorium cerebelli

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.

The sphenoid air sinuses

The spheno-ethmoidal recess

above the superior conchae and anterior to the body.

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

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.

The greater wing

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

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.

The posteriolateral angle projects backwards and has the spine of the sphenoid extending downwards from it

immediately posterior to the foramen spinosum.

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

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

The infratemporal crest

The temporal

infratemporal fossa

The inferior orbital fissure

It leads forward into the orbit.

a horizontal fissure between the greater wing and the maxilla.

the lateral wall

the floor of the medial cranial fossa

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.

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

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.

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

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

The lesser wing

Project laterally from the anterosuperior part of the body

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

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.

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.

the optic canal

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

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

cavernous sinus.

Lateral and medial pterygoid plates

These plates fuse in their upper parts anteriorly but inferiorly they diverge

The medial pterygoid plate

the posterior part of the lateral wall of the nasal cavity

The pterygomaxillary fissure

the pterygoid process of the sphenoid bone and the back of maxilla

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

The pterygoid hamulus

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

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