CSF neuroanatomy

Question 1

How is CSF produced? [3]

Answer 1

In an active (ATP requiring) process.
Na pumped into subarachnoid space through Choroid Plexuses of ventricles
Water follows Na from the blood vessels into the ventricles

Question 2

Where is most choroid plexus found? [4]

Answer 2

• Roof of Temporal Horns of Lateral Ventricles
• Floor of Bodies of Lateral Ventricles
• Roof of Posterior 3rd Ventricle
• Roof of 4th ventricle

Question 3

Through what foramen does CSF travel? [3]

Answer 3

• Foramen of Monro from lateral to 3rd ventricles
• Foramen of Magendie from 4th ventricle to Spinal subarachnoid space (M is for midline)
• Foramina of Luschka from 4th ventricle to cranial subarachnoid space (L is for lateral)

Question 4

How much CSF is produced in the brain? [1]

Answer 4

An adult makes 450-600 CCs of CSF every day [1]

But only maintains ~150CCs in the brain at any point (~25 of which is in the ventricles)

So production = resorption

Question 5

Where is CSF reabsorped? [2]

Answer 5

Through Arachnoid villi [1] within arachnoid granulations along the dural venous sinuses (mainly the sup sagittal) [1]
Unlike production, this is entirely passive

Question 6

How do arachnoid villi work? [1]

Answer 6

A passive process that is a group of pressure-dependant valves
Driven by pressure gradient between ICP & CVP