9 Meninges, venous drainage of brain and CSF

Question 1

What are the 3 layers of the meninges? (outer to inner)

Answer 1

1. Dura mater - tough fibrous rbidges crevices, attached to skull
2. Arachnoid mater - delicate, sealed bag for CSF; bridges crevices
3. Pia mater - delicate, dips into crevices

Question 2

What are cisterns?

Answer 2

Spaces filled with CSF

Question 3

Name 4 cisterns in brain

Answer 3

1. Superior cistern
2. Interpeduncular cistern
3. Cisterna pontis
4. Cisterna magna (cerebellomedullaris)

Question 4

What is a cause of subarachnoid haemorrhage?

Answer 4

berry aneurysm on the circle of Willis

Question 5

Where is a frequent site of subarachnid haemorrhage?

Answer 5

where posterior communicating artery arises form the ICA

Question 6

Why are the roots long at cord end?

Answer 6

1. S1 root origin close to S1 vertebra
2. Vertebral column grows
3. S1 root exits well below its origin in the cord

Question 7

Where is it safe to sample CSF?

Answer 7

Lumbar puncture (subarachnoid space) - needle puncture

• well below L2
• usually L4,5

Question 8

Charatceristics of veins in brain

Answer 8

• thin walls and no valves
• emerge from brain and lie in subarachnoid space
• drain into cranial venous sinuses
• grouped into: eternal (quite variable) and internal cerebral veins