Meninges and Sinuses

Question 1

Periosteal dura:

Answer 1

• lines the inner surface of the skull and serves as the periosteum.
• meningeal dura fuses to the periosteal dura.

Question 2

Within the cranial cavity the dura mater is composed of two layers:

Answer 2

• periosteal dura (attached to skull)
• meningeal dura (fused to periosteal dura)

Question 3

Epidural space in the cranial cavity:

Answer 3

• between the periosteal dura and the skull.
• not normally present, created under abnormal conditions (e.g. bleeding into this plane).

Question 4

In both the cranial cavity and the vertebral canal, the the arachnoid is pressed against the dura via:

Answer 4

• the pressure of the cerebrospinal fluid

Question 5

Dural septa:

Answer 5

• regions where the meningeal dura is not fused to the periosteal dura and separates from the periosteal dura to turn internally to form dural septa.

Question 6

What artery is sandwiched between the periosteal dura and the skull, and is also responsible for the “arterial grooves” on the inner skull?

Answer 6

middle meningeal artery

Question 7

Shearing a middle meningeal artery may lead to what kind of hematoma?

Answer 7

• epidural
  
  • between the periosteal dura and the skull

Question 8

Falx cerebri location:

Answer 8

• lies between the two cerebral hemispheres
• a meningeal dura dural septum

Question 9

Falx cerebelli location:

Answer 9

• lies between the two cerebellar hemispheres
• a meningeal dura dural septum

Question 10

Tentorium cerebelli location:

Answer 10

• lies between the cerebellum and the occipital lobe of the cerebrum.
• a meningeal dura dural septum.

Question 11

Dural venous sinuses structure and location:

Answer 11

• lined with the same epithelium that is found lining the veins of the body.
• between periosteal dura and meningeal dura where the two layers separate.
• within reflections of the meningeal dura.

Question 12

Dural sinuses function:

Answer 12

• carry most of venous drainage from brain.
• communicate with veins of the face, scalp and neck through emissary veins.
• drain into the internal jugular vein

Question 13

Straight sinus location:

Answer 13

• within meningeal dura at the intersection of the falx cerebri and tentorium cerebelli

Question 14

Transverse sinuses location:

Answer 14

• between periosteal and meningeal dura at the attachment of the tentorium cerebelli

Question 15

Confluens of sinuses location:

Answer 15

• between periosteal and meningeal dura at the point where the superior sagittal, occipital and straight sinuses meet

Question 16

Emissary veins:

Answer 16

• veins that connect the veins of superficial regions of the face and scalp to the dural sinuses
• no valves; blood flows via pressure gradient

Question 17

What veins can be pathways for the spread of infection from superficial regions of the face and scalp into the cranial cavity?

Answer 17

emissary veins

Question 18

Cortical (Bridging) Veins:

Answer 18

• carry blood from the brain to the superior sagittal sinus.
• can shear and lead to subdural hemotoma

Question 19

How do Cortical (Bridging) Veins shear?

Answer 19

• superior sagittal sinus is formed from meningeal dura, it does not move with the brain.
• Cortical (Bridging) Veins are tightly bound to the dura, but are not encased in any dura elswhere and move with the brain.
• Large brain movements will cause Cortical (Bridging) Vein shearing.

Question 20

Superior sagittal sinus location:

Answer 20

• between the periosteal dura and meningeal dura at the root of the falx cerebri

Question 21

Inferior sagittal sinus location:

Answer 21

• within a reflection of the meningeal dura at the free edge of the falx cerebri

Question 22

Occipital sinus location:

Answer 22

• between periosteal dura and meningeal dura at the root of the falx cerebelli

Question 23

Sigmoid sinuses location:

Answer 23

• the anterior continuation of the transverse sinuses, drains into
• the jugular bulb

Question 24

Cavernous sinuses location:

Answer 24

• between periosteal and meningeal dura forming the lateral walls of the pituitary fossa

Question 25

Superior petrosal sinuses location:

Answer 25

• connects the cavernous sinus to the sigmoid sinus

Question 26

Inferior petrosal sinuses location:

Answer 26

• drains the cavernous sinus into the jugular bulb

Question 27

Blood flow through the superior sagittal sinus, inferior sagittal sinus, straight sinus, and occipital sinus is all in what direction?

Answer 27

anterior to posterior

Question 28

Where do all of the superior sagittal, occipital and straight sinuses converge?

Answer 28

confluens of sinuses

Question 29

What vein drains into the cavernous sinus?

Answer 29

• superior opthalmic vein
• emissary vein - has superficial facial branches

Question 30

Contents of the cavernous sinus:

Answer 30

1. trabeculae
2. pituitary gland
3. nerves
4. arteries

Question 31

What causes blood flow to be slower in the cavernous sinus?

Answer 31

• trabeculae
• may predispose someone to clotting and/or infection