Meninges and blood supply

Question 1

How many layer of meninges are there and what are their names?

Answer 1

3

• Dura mater
• Arachnoid mater
• Pia mater

Question 2

What are the roles of the meninges?

Answer 2

• Physical protection
• Facilitate flow of CSF
• Provide a framework for blood vessels to supply CNS tissues

Question 3

Where can the dura mater be distinguished as two separate layers?

Answer 3

• Falx cerebri

- Tentorium cerebelli

Question 4

Which nerve supplies the dura mater?

Answer 4

CN V = trigaminal

Question 5

Describe the sub-arachnoid space

Answer 5

It is a true space that has blood vessels running through it and contains CSF.
It is criss-crossed with connective tissue giving a spider web appearance

Question 6

Where does the pia mater follow and merge?

Answer 6

Follows blood vessels into tissue and merges with tunica adventitia (outer layer of blood vessels)

Question 7

What is the epidural space in the spinal cord filled with?

Answer 7

Fat and connective tissue

Question 8

What is a cuff zone?

Answer 8

The point at which meninges stop (after traveling a small distance out with the nerves) and merge with the outside of the nerve
It is easier for drugs to access a nerve at these points

Question 9

Where is the CSF found in the brain?

Answer 9

• sub-arachnoid space

- ventricles

Question 10

What is the channel that runs between the 3rd and 4th ventricles?

Answer 10

mesencephalic aquaeduct

Question 11

Where is the 4th ventricle found?

Answer 11

Caudal to the cerebellum

Question 12

Where is CSF produced?

Answer 12

Choroid plexi

Question 13

Where are the two locations of the choroid plexi?

Answer 13

1. Between the lateral ventricles and 4th ventricle

2. In the roof of the 4th ventricle

Question 14

What are the 3 layers of the blood brain barrier?

Answer 14

Endothelial cells have tight junctions
Thick basement membrane
Foot processes of astrocytes

Question 15

What type of substances can easily pass into the CSF?

Answer 15

Lipid soluble

Question 16

What are the transporting cells in the blood brain barrier?

Answer 16

Ependymal cells

Question 17

Where are the 2 sites of CSF sampling?

Answer 17

• Right behind skull at the junction between the occipital bone and first vertebrae
• At the end of the spinal cord where it narrows as there is less tissue

Question 18

What is the cerebral arterial circle?

Answer 18

Circle of arteries that gives off arteries to supply different bits of the brain

Question 19

Which part of the brain does the cerebral arterial circle go around?

Answer 19

Hypothalamus

Question 20

Why is the source of the arterial supply important to know in industry?

Answer 20

In terms of slaughter technique e.g. halal

Question 21

What are the 2 routes that arterial supply reaches the cerebral arterial circle?

Answer 21

Directly or via rete mirabile

Question 22

What is the purpose of rete mirable?

Answer 22

Cool down the blood and reduce its pulsation/speed

Question 23

What is meant by poor collateral circulation in the brain?

Answer 23

Not much interarterial communication

Blockage of an artery means the blood supply to the tissue is stopped e.g. stroke

Question 24

Where does the spinal cord blood supply branch from?

Answer 24

Vertebral artery and aorta

Question 25

What does the cavernous sinus drain?

Answer 25

Eye and nasal cavity

Question 26

How does the dura mater differ in the spinal cord compared to the brain?

Answer 26

Dura mater is not against the bone in the spinal cord