CSF

Question 1

Where is CSF produced?

Answer 1

In the choroid plexus of the ventricles

Question 2

How is CSF produced?

Answer 2

The production of CSF is an active process:

• Sodium is pumped out into the subarachnoid space
• Water flows back in

Question 3

Turnover of CSF

Answer 3

At a given time there are only 150cc in a human body
Of this only 25cc in the ventricles
This means that the turnover of CSF in the ventricles each day is 3/4 times

Question 4

How much CSF is produced daily?

Answer 4

400-650 cc

Question 5

Pathway of CSF

Answer 5

• Lateral ventricle
• Foramen of monro
• Third ventricle
• Cerebral aqueduct
• Fourth ventricle
• 2x Foramen of lushka- lateral
• Foramen of magendie - medial
• Into subarachnoid space over the brain and spinal cord
• Reabsorbed via venous dural sinuses through arachnoid granulations

Question 6

reabsorption of CSF

Answer 6

Passive process
Controlled by the pressure difference between the ICP and the CVP
Controlled by the arachnoid granulations: one way valve which open when the amount of water in the ICP is 3-5cm greater than the CVP
Arachnoid granulations are PRESSURE dependent

Question 7

What is the function of CSF?

Answer 7

• It bathes the brain and spinal cord
• It protects the brain from shocks which may occur due to rapid movement
• It delivered nutrients and removes waste products