Dural Sinuses, Meninges, and Vasculature

Question 1

What are the cranial meninges made of?

What is the purpose of them?

Answer 1

Dense regular CT

Separate soft tissue of brain from bones of cranium
Enclose and protect blood vessels supply brain
Contain and circulate CSF
FORM some of the veins that drain blood

Question 2

What are the layers of cranial meninges from superficial to deep?

Answer 2

Dura
Arachnoid
Pia

Question 3

What are the two layers of dura mater?

Answer 3

Periosteal

Meningeal

Question 4

What is below the arachnoid mater?

Answer 4

Subarachnoid space (between arachnoid mater and pia mater)

Question 5

What is contained in Pia mater?

Answer 5

Contains cerebral a.

Question 6

What is the arterial supply to the meninges?

Answer 6

Middle meningeal a.

Frontal and parietal Branch

Question 7

What does middle meningeal go thru after coming off of maxillary a.?

Answer 7

Foramen spinosum

Question 8

What is the innervation of the meninges?

Answer 8

V1 - ethmoidal n., tentorial n.
V2- meningeal branch
V3 - meningeal branches
Cervical spinal ns. (C2, 3) - floor of posterior cranial fossa

Question 9

What are the characteristics of the dura mater?

Answer 9

Most Superficial
Toughest and strongest membrane

2 fibrous layers

Question 10

What forms dural venous sinuses?

Answer 10

Separation of periosteal and meningeal layers

Question 11

When is a subdural space created? and where?

Answer 11

When something goes wrong, as in a bleeding bridging v. (Subdural hematoma)

Space b/w dura mater and arachnoid

Question 12

What is arachnoid mater made of?

Answer 12

Arachnoid traveculae (a delicate web of collage and elastic fibers)

Question 13

What is deep to arachnoid mater? What is here?

Answer 13

Subarachnoid space

CSF

Question 14

What does pia mater do?

Answer 14

Tightly adheres to brain and follows every contour of the brain surface

Question 15

What makes a septa? What is a septa?

What are the 4 septa?

Answer 15

Septa: flat partition into cranial cavity Separating specific parts of brain

Made from extension of meningeal layer of dura mater

Falx cerebri; tentorium cerebelli; falx cerebelli; diaphragma sellae

Question 16

What’s purpose of falx cerebri?

Answer 16

Separates two hemispheres of cerebrum

Question 17

What’s purpose of falx cerebelli?

Answer 17

Separates two hemispheres of cerebellum

Question 18

What’s purpose of tentorium cerebelli?

Answer 18

Separates cerebrum from cerebellum

Question 19

What’s purpose of diaphragma sellae? Where is it?

What sinus is here?

Answer 19

Superior to hypophyseal fossa of sphenoid bone and pituitary gland
Attaches to anterior and posteiror clinoid processes

Opening in middle for passage of pituitary infundibulum

Cavernous sinus

Question 20

What is found within the septa?

Answer 20

Dural venous sinuses

Question 21

What are the dural venous sinuses?

Answer 21

Superior and inferior sagittal sinuses
Straight sinus
Sigmoid sinus
Transverse sinus

Question 22

What happens during an epidural hematoma?

How do you get one?

How does it present?

how does it look on a CT?

Answer 22

Ruptured middle meningeal artery

If you get hit in side of head at pterion point

With a lucid interval where blood slowly fills up space and with brain herniating out

“Lens”

Question 23

What happens during an subdural hematoma?

How do you get one?

How does it present?

how does it look on a CT?

Answer 23

Rupture briding v.

Acceleration/deceleration injury
Shaken baby syndrome

Crescent shaped

Question 24

What happens during an Subachanoid hemorrhage?

How do you get one?

How does it present?

how does it look on a CT?

Who is predisposed to it?

Answer 24

Ruptured aneurysm on cerebral a.

Fills subarachnoid space

“The worst headache of my life”
Can even see it during lumbar puncture if there is blood in CSF

Spiderweb on CT

Postmenopausal women and people w/ hypertension

Question 25

Contributing veins to cavernous sinus? What does this allow for?

Answer 25

Superior opthalmic v. Inferior ophthalmic v. Facial v. (Incl. angular v.) Allow for an infection in the front of the face to spread back

Question 26

What helps drains the cavernous sinus?

Answer 26

Superior petrosal Inferior petrosal sinus: Goes from cavernous to sigmoid

Question 27

What is the associated Neurovascular strucutre in the cavernous sinus?

Answer 27

ICA CN 3, 4, v1, V2, 6 Diaphragm sellae

Question 28

What is a Cavernous Sinus Thrombosis? | Clinically presents with?

Answer 28

Compress CN3, 4, V1, V2 and 6 (6 is mostly affected bc of its proximity) High fever, periorbital edema, CN palsies, decreased visual acuity

Question 29

What are the 4 parts of the ICA? Which part will give off cerebral arteries? What do they form?

Answer 29

Cervical, petrosal, cavernous, and cerebral Cerebral gives off cerebral As. In the Circle of Willis

Question 30

What is the CSF?

Answer 30

Clear colorless liquids that circulate sin ventricles and subarachnoid space

Question 31

What are the functions of CSF?

Answer 31

Buoyancy Protection Environmental stability

Question 32

What is CSF formed by and produced by?

Answer 32

Formed by choroid plexus in each ventricle Produced by ependymal cells

Question 33

Where do ependymal cells originate from and what do they do?

Answer 33

Originate from blood plasma Secrete and produce CSF

Question 34

What is the makeup of CSF?

Answer 34

Similar to blood plasma but has greater amount of Na, H, Ca | Less K

Question 35

What doe arachnoid granulation do?

Answer 35

Help csf flow to dural venous sinus

Question 36

What happens to the arachnoid granulation if there is a subarachnoid hemorrage? What is this called?

Answer 36

Blood is flowing into subarachnoid space Cannot be filtered out thru arachnoid granulation (will damage granulation, causes them to fibrose, and clog whole system) Causes enlargement of ventricle and compression of brain = Hydrocephalus

Question 37

What is the danger triangle? | What is this implicated in?

Answer 37

Triangular area from upper lip to the bridge of nose Thrombophlebitis of facial v. Facial v. Makes connection w/ cavernous sinus and could allow an infection of the face to spread to cavernous sinus and pterygoid venous plexus Facial v. Has no valves so blood can go backwards and enter cavernous sinus