3. DURAL VENOUS SINUSES
These are the various venous
channels present in the cranial
dura.
They are formed in the following
two ways:
1. By the separation of two layers of
cranial dura.
2. By the reduplication of the
meningeal layer.
4.
5.
6.
7. CHARACTERISTICS & FUNCTIONS
Lined with endothelium
Devoid of muscular coat & valves.
Drain the blood from brain, meninges &
bones of skull.
Some venous sinuses also receive
CSF.
Receive valveless emissary vein to
maintain an equilibrium of venous
pressure.
14. CAVERNOUS SINUS
Paired dural venous sinus
Situated in the middle cranial fossa,
on either side of body of the sphenoid
bone and sella turcica in the middle
cranial fossa.
16. Formation: separation between
meningeal & endosteal layer of
duramater.
Size:
Length : 2 cm
Breadth : 1cm
Extent:
Front – superior orbital fissure
Behind - apex of petrous part of
temporal bone
27. STRUCTURES PASSING THROUGH THE
SINUS
Internal carotid artery:
• Surrounded by sympathetic
plexus, Runs along floor (carotid
sulcus)
Abducent nerve:
• Inferolateral to ICA
28.
29. Structures Present in the Lateral
Wall of the Sinus:
1) Oculomotor nerve.
2) Trochlear nerve.
3) Ophthalmic nerve.
4) Maxillary nerve.
30. TRIBUTARIES
The cavernous sinus receives
blood from three sources: orbit,
meninges, and brain.
Hence, its tributaries come from
these sources as follows:
31. FROM ORBIT
Superior ophthalmic vein.
Inferior ophthalmic vein.
Central vein of retina.
40. 4. Facial vein via two routes:
(a) Superior ophthalmic vein →
angular vein → facial vein
(b) Emissary veins → pterygoid
venous plexus → deep facial vein
→ facial vein.
41.
42.
43. Opposite cavernous sinuses via
anterior and posterior
intercavernous sinuses.
Superior sagittal sinus via
superficial middle cerebral vein and
superior anastomotic vein.
Internal vertebral venous plexus,
via basilar venous plexus.
45. CAVERNOUS SINUS
THROMBOSIS
Septic thrombosis of cavernous sinus -
by communication from dangerous area
of face, orbit and pharynx
Severe pain in eye and forehead
Ophthalmoplegia due to involvement of
3rd , 4th and 6th cranial nerves
marked oedema of eyelids
Exophthalmos
46. PULSATING EXOPHTHALMOS
Pulsating exophthalmos
internal carotid artery is ruptured as
a result of fracture of base of skull –
arterio- venous communication is
established.
ligation of inernal carotid artery may
be helpful, but patient may develop
contralateral hemiplegia.