Dural Venous Sinuses

Question 1

What two layers make up the Dura Mater

Answer 1

Periosteal Layer- most superficial layer and attaches to the periosteum of the cranial bones

Meningeal layer-lies deep to the periosteal layer

The meningeal layer will separate to creat a large blood filled space called a dural venous sinus

Question 2

Emissary Vein

Answer 2

drains blood from the scalp to the dural sinuses

Question 3

Bridging Vein

Answer 3

Drains from the brain into the sinus

Question 4

Sub dural space

Answer 4

Space between the arachnoid mater and the overlying dura mater

this is a potential space

Question 5

Arachnoid mater

Answer 5

imediately internal to the dura mater

composed of web of collagen and elastic fibers called the arachnoid trabeculae

Question 6

Subarachnoid space

Answer 6

Immediately deep to the arachnoid is considered the arachnoid space

Cerebrospinal fluid travels through here as well as arteries travel in this space

Question 7

Pia Mater

Answer 7

Most intermost cranial meninge

thin layer of delicate connective tissue that tightly adheres to the brain and follows every contour of the brain surface

Question 8

Cranial Dural Septa

Answer 8

The meningeal layer of the dura mater extends flat partitions (septa) into the cranial cavity

Provide stabilization and support of the brain

Fal cerebri
Tentorium cerebelli
falx cerebelli
diaphragma sellae

within the septa contain the venous sinuses

Question 9

Arterial supply to the meninges

Answer 9

Middle Meningeal artery which comes off of maxillary artery and through foramen spinosum

Middle meningeal Artery has a frontal branch, and a parietal branch

Question 10

Innervation of the Meninges

Answer 10

CN V1: Anterior portion via ethmodial nerve
Posterior portion via Tentorial nerve

CN V2: Anterolateral via the Meningeal branch of maxillary nerve

CN V3: Lateral part via the meningeal branches of the mandibular nerve

C2, C3: to floor of posterior cranial fossa

Question 11

Epidural Hematoma

Answer 11

Rupture of the middle meningeal artery

this occurs between the skull and the dura mater of where the middle meningeal a is located

can be cause by breaking of Emissary Veins

Convex lens view on CT due to tight adherence to sutures of the skull

Question 12

Blow to the Pterion

Answer 12

Can damage the Middle meningeal which runs directly behind it and because this area of the skull is much thinner

Lead to the Epidural Hematoma
-symptoms would be a dizziness and headache, lucid interval due to the delay of the time for the bleeding to build up

Question 13

Subdural Hemorrhage

Answer 13

breaking of the Bridging Vein

Bleeding occurs in between the dural layer and subarachnoid layer

can be caused from acceleration and deacceleration injuries (shaking baby syndrome)

occurs in old people more frequently due to atrophy of the brain and more room in the skull for mvmt of the brain

Crescent view on CT scan

Question 14

Subarachnoid Hemorrage

Answer 14

usually caused by ruptured aneurysm

bleeding into the subarachnoid space

Anterior Cerebral artery-40%
Middle Cerebral Artery-34%
Internal Carotid Artery-20%

Spider Web on CT scan

Question 15

What veins play an anastamois between the Dural venous sinuses and face

Answer 15

supra orbital vein
Superior opthalmic vein
inferior opthalmic vein
all coming off facial vein

they all dump from cavernous sinus

An infection could travel back to the brain from the face via these veins

Question 16

If their is swelling in the cavernous sinus, what structures may be impinged

Answer 16

Oculomotor (CN III)
Trochlear (CN IV)
Abducent (CN VI)

Opthalmic (V1)
Maxillary (V2)

Optic CNII (maybe)

Internal carotid Artery

Question 17

Cavernous sinus thrombosis

Answer 17

High fever
periorbital edema and chemosis (conjunctival edema)
cranial nerve palsy, (CN VI most common)
decreased visual acuity

fix with IV of ABX
Heparin and surgical consultation

Question 18

Cerebrospinal Fluid

Answer 18

Helps the CNS with buoyancy, protection, and environmental stability

formed via the choroid plexus in the ventricles from the ependymal cells

similar to blood plasma but has greater sodium, hydrogen, and calcium

but less potassium

Question 19

How does the CSF drain into the Dural sinuses

Answer 19

via the Arachnoid granulations

these pass through the arachnoid and the meningeal layer of the dura mater

Question 20

Hydrocephalus

Answer 20

a bleed or blood that gets into the CSF that when it tries to filter through the arachnoid granulations if damages them and cause them to fibrous and stop working

then the ventricles will fill up with CSF that will cause the brain to expand especially in babies if the skull is much more soft and not connected