CSF formation and absorption

Last reviewed 06/2023

CSF is produced at a rate of 500 millilitres a day in adults, predominantly by the choroid plexus of the lateral, third and fourth ventricles.

Flow is caudal through the ventricular system and into the subarachnoid space through the foramina of Luschka and Magendie. It passes through the tentorial hiatus and over the hemispheric convexity whereupon it is absorbed into the venous system through the arachnoid granulations.