Dural Sinuses, Meninges, and Vasculature

Question 1

What are the basic features of dura matter?

Answer 1

Tough membrane of two fibrous layers:

• periosteal: more superficial, attaches to the periosteum of cranial bones
• meningeal: deeper layer

Strongest of the meninges

Question 2

What happens in areas where the meningeal and periosteal layers of the dura matter separate?

Answer 2

Form large blood-filled spaces called dura venous sinuses

Question 3

Where does the emissary v. travel?

Answer 3

From the scalp to the dural venous sinus

Question 4

Where does the bridging v. travel?

Answer 4

from the cortex to the dural venous sinus

Question 5

Where is arachnoid matter found? What are its structural characteristics

Answer 5

Immediately internal to the dura matter

Delicate web of collagen elastic fibers= arachnoid trabeculae

Question 6

What is the subdural space?

Answer 6

A POTENTIAL space between the arachnoid and dura matter

Question 7

What can cause you to see the subdural space?

Answer 7

Bleeding from the bridging vein which then bleeds into the subdural space

Following a lumbar puncture, when you pull out fluid it creates a negative pressure creating space

Question 8

What is found in the subarachnoid space?

Answer 8

Cerebral spinal fluid

Question 9

What artery can be found in the subarachnoid? Where does this come from?

Answer 9

Cerebral arteries

Internal carotid –> circle of willis –> cerebral arteries

Question 10

What can cause you/put you at risk for having an aneurysm in a cerebral artery?

Answer 10

Polycystic kidney disease
Elhers Danlos
Post meopause women: less estrogen –> less cartilage –> weaker blood vessels
Hypertension

AKA anything that weakens your blood vessels

Question 11

What is the unique characteristic of Pia matter in comparison to the other meningeal layers?

Answer 11

It is the only layer that follows every contour of the brain, thin connective tissue that adheres tightly to brain

Question 12

What is a cranial dura septa? What is contained in these septa?

Answer 12

An extension of the meningeal layer of the dural matter deep into the cranial cavity which provides stabilization and support

Dural venous sinuses

Question 13

Where are the four locations of the cranial dural septa? What do they divide?

Answer 13

Falx cerebri (negative mohawk): sagital, separates 2 hemispheres
Tentorium cerebelli: horizontal, separates cerebellum and cerebrum
Falx cerebelli: sagital, separates cerebellum
Diaphragm sellae: overlies pituitary gland, cavernous sinuous

Question 14

What is the main arterial supply of the meninges? Where does it branch from? What does it pass through?

Answer 14

The middle meningeal artery

external carotid –> maxillary artery –> middle meningeal artery

foramen spinosum

Question 15

What happens when you haver a ruptured middle meningeal artery?

Answer 15

Epidural hematoma

Symptoms: hit in side of head at first fell okay then blood pools up and reach threshold and brain can’t take it so herniation

Question 16

Why is rupturing of the middle meningeal artery a common trauma? What does this look like on a scan?

Answer 16

It passes under the Pterion which is a junction of the frontal, parietal, spehnoid, and temporal bones that has a thinner skull

Convex lens

Question 17

What happens when you rupture a bridging vein? How can this happen? What does it look like on a scan?

Answer 17

Subdural hemorrhage

Old person in an acceleration deceleration accident ie car crash, fall
Shaking baby syndrome

Crescent

Question 18

What is located in the cavernous sinus?

Answer 18

Oculomotor N.
Trochlear N.
Abducent N.
Trigeminal N. (only ophthalmic and maxillary branches) 
Internal Carotid A.
Pituatary Gland
Diapghragma Sellae 
Infundibulum

Question 19

What are the 4 parts of the internal carotid artery? How does it travel?

Answer 19

Cervical
Petrous
Cavernous
Cerebral

Up and anteromedially

Question 20

What can happen when you have cavernous sinus thrombosis?

Answer 20

High fever
Preorbital edema and chemosis (conjunctival edema)
Cranial nerve palsy: most common is CN VI, can’t gaze one eye laterally
Decreased visual acuity

Question 21

What forms cerebrospinal fluid? What are the cells that secrete it?

Answer 21

Choroid plexus of each ventricle

Ependymal cells (originate from blood plasma but have less potassium)

Question 22

What is the role of the arachnoid granulation?

Answer 22

Helps flow of CSF from subarachnoid space into venous system

granulation –> dural sinus –> internal jugular vein

Question 23

How does hydocephalis occur?

Answer 23

Blood in subarachnoid space, arachnoid granulation is not ready because deals with CSF –> fibrosis of arachnoid granulation -> CSF keeps being produced but nowhere to go –> enlargement of ventricles