2. Position & Extension
-on the side of the body of sphenoid,
-extending from the apex of the petrous temporal bone (behind)
to the medial end of the superior orbital fissure (in front).
-Each sinus is 2 cm long and 1 cm wide,
6. * Medially:
• Sphenoidal air sinus.
• Hypophysis cerebri.
* Laterally:
• Trigeminal ganglion.
• Uncus of the temporal lobe.
* Nerves in its lateral wall: (from above downwards)
• Oculomotor nerve.
• Trochlear nerve.
• Ophthalmic division of trigeminal nerve.
• Maxillary division of trigeminal nerve.
* Structures within its cavity.
• Internal carotid artery.
• Abducent nerve (on the lateral side of the artery).
• -carotid sympathetic plexus
• N.B.: The internal carotid artery may rupture inside the cavernous sinus due to
fracture base of the skull. This results in a pulsating swelling behind the orbit.
10. Cavernous Sinuses
Optic Chiasma
Internal Carotid Artery
Uncus
of Pituitary
Sphenoidal Temporal Lobe Gland
Air Sinus
Sphenoidal
AirSinuses
Body
of
Sphenoid Bone
11. Medial end of
The superior orbital fissure
Uncus
Optic Chaisma
Temporal lobe
Apex of petrous
Trigeminal Ganglion
12. Content of the Cavernous Sinuses
Occulomotor Nerve
Trochlear Nerve
Ophthalmic Nerve
Maxillary Nerve
Internal carotid Artery
Abducent Nerve with
Sympathetic Plexus
14. Anteriorly:
• Ophthalmic veins (connect it with the facial vein in the face).
• Sphenoparietal sinus.
Posteriorly:
• Superior petrosal sinus (connects it with the transverse sinus).
• Inferior petrosal sinus (connects it with the internal jugular vein).
Medially:
• Anterior and posterior intercavernous sinuses (connect the 2cavernous sinuses together).
Superiorly:
• Superficial middle cerebral vein (from the lateral surface of the
• brain).
• Cerebral veins from the inferior surface of the brain.
Inferiorly:
• Emissary vein through the carotid canal (connects it with the internal jugular vein).
• Emissary vein through the foramen ovale (connects it with the pterygoid plexus of
veins).
15. Superior and inferior
Ophthalmic veins
Plexus of emissary veins through
carotid canal to internal jugular vein
inferior
Petrosal sinus
18. In
fe Ce
rio
Cerebral vein
nt
ro th ral
Superficial middle
Su
pe ph e ve
th re in
Sphenoparietal sinus
r io al tin o
ro m a f
ph ic
th ve
al in
m
Su ic
pe ve
r io in
ro
ph
th
Ri
al
g
m
veins
In
ht
fe ic
sinus
rio ve
Ca
in
Inferior cerebral
ro
ve
ph
rn
Superior petrosal
th
al
ou
m
s
ic
S
Ce ve
in
inu
nt
s
th ral v
e
re ein
tin o
a f
Le
f
In
tC
In f
a
te er
ior
ve
rc
rn
sin ave sin pet
ou
us rn us r os
es ou a l
s
sS
inu
s
In
f er
ior
sin pet
us r os
a l
veins
Sphenoparietal sinus
Su
pe
Inferior cerebral
rio
Cerebral vein
si r p
nu et
Superficial middle
s ros
al
20. s
i nu
S
s
n ou
r
ve
Ca
ht
Rig us
S in
s
ou
e rn
av
tC
Lef
Foramen Vesalius
Foramen Ovale
Foramen Lacerum
Pharyngeal Pterygoid
Plexus Plexus
21. 8- Inferior Petrosal Sinus
s
i nu
S
s
n ou
r
ve
Ca
ht
Rig us
S in
s
ou
e rn
av
tC
Lef
Foramen Vesalius
Foramen Ovale
1- Superior Ophthalmic Vein Foramen Lacerum
2- Inferior Ophthalmic Vein
3- Sphenoparietal sinus
4- Anterior Facial Vein Pharyngeal Pterygoid
Plexus Plexus
24. -The flow of blood in all the tributaries and communications of the
cavernous sinus is reversible because they possess no valves.
-Spread of infection to the cavernous sinus leads to its thrombosis.
-The cavernous sinus communicates with the veins draining the
middle area of the face (dangerous area of the face) through 2
routes:
1-Superior ophthalmic vein.
2-Deep facial vein, pterygoid plexus of veins and emissary vein
through the foramen ovale.
26. If the cavernous sinus is thrombosed what are the important structures that
may be affected??
Q. What is the clinical picture of CST ?
• A. Clinical features of CST
• General features of infection: fever, rigors, malaise, and sever frontal and orbital headache.
• Unilateral exophthalmos and tender eye ball
• Oedema of the eyelid and chemosis of the conjunctiva (due to obstruction of the superior and inferior ophthalmic veins).
• Third, fourth, sixth cranial nerves and ophthalmic and maxillary divisions of the fifth cranial nerve may be affected
(paralysis or paresis):
• * Clinical picture of oculomotor paralysis:
– External ophthalmoplegia: Paralysis of movements of the affected eye (upward, downward and medial). Ptosis: due
to paralysis of the levator palpebrae superioris. Slight exophthalmos.
– Internal ophthalmoplegia: Dilated fixed pupil with loss of accommodation reflex. (due to paralysis of the sphincter
papillae and cilliary muscles).
• *Paralysis of abducent nerve: Paralysis of outward movement of the affected eye.( due to paralysis of lateral rectus
muscle)
• * Paralysis of trochlear nerve: Paralysis of outward and downward movement of the affected eye. (due to paralysis of
superior oblique muscle)
• * Anesthesia in the distribution of ophthalmic division of the trigeminal nerve, decreased or absent corneal reflex and
possibly anesthesia in the maxillary branch distribution.
• 5 . Infection can spread to the contralateral cavernous sinus within 24–48 hr of initial presentation. The earliest feature of
such spread is affection of the abducent nerve (6 th cranial nerve) on the opposite side (paralysis of outward movement of the
affected eye).