a clear colorless, sterile, extravascular fluid that circulates in the

ventricles of the brain the subarachoid spaces & the spinal cord.

90 to 150 mL= normal CSF of the adult

10 to 60 mL = newborn

∞ Most common method of collection: Lumbar puncture (between the 3rd or 4th lumbar

vertebrae, or between the 4th and 5th lumbar vertebrae)

∞ Other methods: cisternal puncture, lateral cervical puncture

Main functions of CSF

1. Serve as mechanical buffer

2. Regulates the volume of intracranial contents

3. Provides nutrient medium for CNS

4. Acts as excretory channel for metabolic products of CNS.