Download The lesser wing

The body
The greater wing
The lesser wing
Lateral plate
medial pterygoid plate
one bone
two bones
two bone
two bone
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 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).
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
a horizontal fissure between the greater wing and the
maxilla.
It leads forward into the orbit.
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.