It circulates up over the central hemispheres and down around the spinal cord.
It is actively removed by the arachnoid granulations located over the cerebral hemispheres.
CSF formation occurs by:
active transport
ultrafiltration of plasma.
The total volume of CSF is about:
130 ml of which on average 25 ml is ventricular.
Evidence suggest that the daily secretion is about :
750 ml implying a fairly rapid turnover