Meninges and Dural Sinuses

Question 1

Function of Meninges:

Answer 1

Support: forms framework for dural sinuses
Protection: cushions the brain– Prevents damage from trauma
Continuous around spinal cord

Question 2

What are the three layers of the meninges?

Answer 2

Pia matter: deepest surrounds brain
Arachnoid matrer
Dura mater: Outermesh

Question 3

What will you find in the subarachnoid space?

Answer 3

Trabecular, villi, vascular components

Question 4

What are the potential spaces?

Answer 4

Epidural (between bone and dural

Subdural (between dura and arachnoid

Question 5

What are the actual spaces?

Answer 5

Subarachnoid space

Question 6

What compartments does the Dural septa create in the brain?

Answer 6

• Falx Cerebri: Separates the two hemisphere of cerebellum

- Tentorium cerebelli: Separates cerebrum from cerebellum. Creates landmark and venous channels

Question 7

What are the Dural sinuses?

Answer 7

1. Superior sagittal (falx cerebri)– easy landmark
2. Inferior sagittal (falx Cerebri) Runs into straight sinus
3. Straight: In junction between fall cerebri and tentorium– Junction of f. Cerebri and tentorium
4. Occipital (falx cerebelli)

NOTE: 1-4 flow in anterior to posterior direction (towards occipital pole) creating confluence of sinuses

The R and L transverse will drain from confluence

Question 8

The superior ophthalmic vein:

Answer 8

Drains posterior into cavernous isnus

Question 9

Cavernous Sinus has:

Answer 9

Lost of N. (carotid plexus) and internal carotid

Question 10

Superior and inferior petrosal:

Answer 10

lie on petrosal bone and dump into sigmoid sinus

Question 11

Sigmoid:

Answer 11

S-shaped: receives blood from transfers sinuses and cavernous sinus

Question 12

Internal jugular:

Answer 12

Dumps blood and CSF black to venous system

Question 13

Anterior blood supply to Dura:

Answer 13

Ophthalmic (IC)
Ethmoidal (ophthalmic a.)
Midle Meningeal (maxillary)*** Primary supply

Question 14

Middle blood supply to Dural:

Answer 14

Middle Meningeal**
Accy meningeal
Ascending pharyngeal (EC)

Question 15

Posterior blood soppy to dural:

Answer 15

Occipital (EC)
Vertebral (subclavian)
Ascending pharyngeal (EC)

Question 16

Nerve supply to Anterior portion of dura:

Answer 16

V1

Question 17

Nerve supply to Posterior portion of Dura:

Answer 17

Mainly CN X, small amount by C1 and C2

Question 18

Nerve supply to middle:

Answer 18

V1-3

Question 19

What is the arachnoid layer?

Answer 19

Arachnoid barrier layer (also secretion): adherent to dura via tight junctions

Subarachnoid space (CSF and vessels- arteries)

Arachnoid Villi: Specialized structures from arachnoid tissue, Protrude into sinus

Question 20

Pia:

Answer 20

Tightly adherent to neural tissue. Continuous over entire surface of the brain

Question 21

Epidural Hemorrhage:

Answer 21

Middle Meningeal artery

Question 22

Subdural Hemorrhage:

Answer 22

Dural Venous sinus

Question 23

Subarachnoid Hemorrhage:

Answer 23

Cerebral artery or vein (aneurysm or trauma)

Question 24

stroke Hemorrhage:

Answer 24

Middle cerebral artery

Question 25

Herniation of brain:

Answer 25

1. Increasing cranial pressure:
   - Midbrain maybe be pushed against tentorium
   - Can herniate from one dural compartment to another: Temporal lobe through tectorial notch– coma
   - Cerebellum into foramen magnum= fatal