3. Meninges, venous drainage of the brain and CSF

Question 1

Which layer of dura is the cerebral artery embedded in?

Answer 1

Pia mater

Question 2

Describe the 3 layers of dura mater?

Answer 2

Dura: Outer, tough fibrous bridges crevices, attached to the skull
Arachnoid: Middle, delicate, sealed bag for CSF, bridges crevices
Pia: Inner, delicate, dips into crevices

Question 3

What is a cistern?

Answer 3

spaces filled with CSF

Question 4

Name the 4 cisterns?

Answer 4

Superior cistern
Cisterna magna (cerebellomedullaris)
Cisterna pontis
Interpeduncular cistern

Question 5

Where is a frequent site for a berry aneurysm to develop on the circle of willis?
Risk?

Answer 5

Where the posterior communication artery (PCA) arises from Internal cerebral artery
RIsk? Subarachnoid haemorrhage development as the arterial circle of the willis lies a subarachnoid space

Question 6

Why are the roots long at the 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

What is the position of veins of the brain>

Answer 7

IN subarachnoid space where they then drain into cranial venous sinuses

Question 8

What are the main sinuses of the brain?

Answer 8

Superior sagital sinus
Straight sinus
Transverse sinus
(all meet at the confluence of sinuses at the dorsal surface of the head)

Question 9

Name the internal cerebral veins?

**

Answer 9

Internal cerebral vein
Great cerebral vein (aka vein of galen)
Basal vein

Question 10

Name the deep veins above the thalamus?

Answer 10

Great cerebral vein (vein of galen)
Basal vein
Internal cerebral vein
Choroidal vein
Thalamostriate vein

Question 11

Which venous sinuses are related to the tentorium?

Answer 11

Transverse
Straight
Confluence of sinuses
Superior and inferior petrosal sinus
Cavernous sinus

Question 12

Name the dural folds inside the skull?

Answer 12

Falx cerebi (in the midline)
Tentorium cerebelli  (at the axial plane)
Tentorial notch (i.e. due to the opening between the above to allow communication between hemispheres)

Question 13

How is CSF formed?

Answer 13

Formed in the choroid plexus (up to half from blood vessels surrounding the ventricles)
This is a core of vascular tissue (in pia) covered by an epithelium which secretes CSF

Question 14

How does CSF move out of the ventricular system?

Answer 14

CSF flows out of ventricle system into subarachoid sp. via apertures in fourth ventricle through

Question 15

Where does CSF get absorbed?

Answer 15

Firstly in subarchnoid space at arachnoid granulation then finally are superior sagittal space
Hence flow is from 4th ventricle, then outwards and upwards to the superior sagittal sinus where it is finally absorbed. Leads to 4x turn over a day

Question 16

What is hydrocephalus?

Caused by?

Answer 16

Condition where there is fluid accumulation in the brain. Leading to head enlargement and potentially brain damage.

Can be due to blocked transport (non-communucative) or to overproduction/blocked absorption of CSF (communicative)

The ventricles enlarge causes compression from the inside