CSF and ICP

Question 1

Where is CSF produced?

What cell is responsible?

Answer 1

Choroid plexus in the ventricles in the brain

Ependymal cells

Question 2

Name the ventricles of the brain?

Answer 2

Left lateral
Right lateral
3rd ventricle
4th ventricle

Question 3

What makes up the majority of CSF?

Answer 3

Water

Question 4

Once the CSF is produced in the ventricles, it passes through the foramen of … (medially) and foramen of … (laterally) mainly into the … space (but some passes into the … canal).

It is then reabsorbed via the … granulations into the … … sinuses.

Answer 4

Once the CSF is produced in the ventricles, it passes through the FORAMEN OF MAGENDIE (medially) and FORAMEN OF LUSCHKA (laterally) mainly into the SUBARACHNOID space (but some passes into the CENTRAL canal).

It is then reabsorbed via the ARACHNOID granulations into the DURAL VENOUS sinuses.

Question 5

Name the 4 layers of meninges that protect the brain and spinal cord. From deepest to most superfical

Answer 5

Pia mater (“faithful mother” - follows every wee nook n cranny of the brain)

Subarachnoid space

Arachnoid mater

Dura mater (durable top coat)

Question 6

What provides the sensory supply to the dura mater?

Answer 6

CN V

Question 7

What part of the meninges is responsible for enclosing the dural venous sinuses?

Answer 7

Dura mater

Question 8

At what point in the spine does the subarachnoid space end?

Answer 8

S2

Question 9

Once the CSF is produced by the lateral and third ventricle. What does it have to pass through to reach the 4th ventricle?

Answer 9

Cerebral aqueduct

Question 10

What is the average ICP?

Answer 10

~8-13mmHg

Question 11

Explain how the optic ‘nerve’ can become compressed if ICP rises.

What condition arises as a result of this?

Answer 11

The optic ‘nerve’ is actually just a bilateral extension of the forebrain and is the neural bundle, central artery and vein of retina covered in meninges

If ICP raises it will be transmitted along the subarachnoid space -> compressed optic nerve -> PAPILLOEDMEA

Question 12

What are the dural septae?

What is the name of the following dural sepate?

• that divides 2 cerebral hemispheres?
• that lies over the cerebellum?
• what divides the 2 lobes of the cerebellum?
• that lies over the pituitary gland?

Answer 12

2 cerebral hemispheres = falx cerebri
Over cerebellum = tentorium cerebelli

Between cerebellum = falx cerebelli
Over pituitary gland = diaphragma sellae

Question 13

If ICP rises, nerves can be compressed/stretched. What visual defect happens as a result of compressing/stretch of:

• CN III
• CN IV
• CN VI

Answer 13

CN III

• impaired IO, SR, MR, IR
• ‘down and out’ position - SO and LR in charge

CN IV

• impaired SO
• can’t look in and down (notice when trying to walk down stairs etc. - will experience diplopia)

CN VI

• impaired LR
• eye medially deviated