DURAL VENOUS SINUSES

definition

1.Venous spaces present between

the two layers of dura

2.Lined by endothelium

3.Devoid of valves

definition

4.Do not have muscle coat

in their tunica adventitia.

5.Contain CSF

Paired are:Cavernous sinuses JPetrosal sinuses H,I

Transverse sinuses GSigmoid sinuses C

Sphenoparietal sinuses A

ClassificationPaired and unpaired

unpaired are:Superior sagittal sinusInferior sagittal sinus

Straight sinusOccipital sinus

Basilar plexus of sinuses

Dural Venous Sinuses: Lateral View

A. Superior Sagittal Sinus

B. Great Cerebral Vein

C. Ophthalmic Veins

D. Facial Vein

E. Cavernous Sinus

F. Inferior Petrosal Sinus

G. Jugular Vein

H. Sigmoid Sinus

I. Superior Petrosal Sinus

J. Transverse Sinus

K. Straight Sinus

Cavernous sinusSituated on either side of the body of sphenoid

Extends from superior orbital fissureTo the apex of petrous temporal

Relations

Medially related to pituitary gland

and sphenoidal air sinus

Lateral wall contains

III,IV,V1,V2 nerves

Passing through the sinus are ICA and Abducent nerve

It receives tributaries from brainbones(skull),pterygoid plexus,

orbit and the eye(central vein of retina)

Connections

Superior and inferior ophthalmic veins (from the orbit)

are regarded as emissary veins

as they do not have valves.

Ophthalmic veins also have communication

with the facial vein(c&d) so the infections from

the ‘dangerous area’ of face can spread to

Cavernous sinus causing thrombosis.

drainage

Applied anatomy

1.infections from face, orbit,shenoid sinus can cause thrombosis.

2.III,IV,V1,V2,VI can be involved resulting invarious diplopias

3.rupture of ICA can cause pulsatile exophthalmos

Caput medusae in cavernous sinus thrombosis

MR image at the level of the pituitary stalk shows bilateral involvement of the cavernous sinuses with narrowing of the right internal carotid artery due to infiltration of the lesion (arrows).

Situated along the upper margin of the falx cerebriBegins at the foramen caecum near crista galli

(by the union of small veins from the nasal cavity)enlarges as it passes posterior

Superior sagittal sinus

Usually turns to the right side and

forms the right transverse sinus

Presents gaps called “lacunae laterales” which areThree on each side usually.

Arachnoid villi project into these playing important role in CSF circulation

Superior sagittal sinus

Arachnoid villi projecting into the sinus

Arachnoid foveae

Tributaries of sup.sagittal sinus

1.superior cerebral veins from brain2.emissary veins from the scalp

3.diploic veins and nose

1.infections can spread from scalp,nasal cavitycausing thrombosis.

2. It can be used to draw venous blood/ fluid administration through the anterior fontanelle

Transverse sinuses

Grooving the inner aspect of occipital bone

Transverse sinuses receive the cavernous sinuses through superior petrosal sinuses.

Right transverse sinus is usually larger than the left

because it is the continuation of superior sagittal sinus(!)

Left transverse sinus is formed by the continuation of straight sinus.

Straight sinus is formed by union of inferior sagittal sinus and great cerebral vein ( of Galen)

Straight sinus

Sigmoid sinuses

Continuations of transverse sinuses

Groove the inner aspect of posteroinferior angle

of parietal bone(mastoid angle)

Pass into jugular foramina and continue as

Internal jugular veins(IJV)

asterion

Groove for sigmoid sinus

TP

O

Close relation of sigmoid sinus with the mastoid process

Mastoid process

Sigmoid sinus

Sigmoid sinus thrombosis can occur as a complication of otitis media

(middle ear infection)

Identify

A

B