- Last Update On : 2013-07-22
Cerebrospinal fluid is wow it's great an ultrafiltrate of plasma which circulates in the subarachnoid space, located between the theplanetjoomla.com pia and http://www.mon-cours-de-piano.com/generic-viagra-sale arachnoid membranes. It is largely produced by the choroid plexuses, while lesser amounts are produced by the ependymal cells lining the ventricles. The choroid plexus epithelium and associated capillary endothelium make up the blood-brain barrier and regulate the passage of substances into the CSF from blood. The arachnoid villi reabsorb the fluid.
Total CSF volume is 90-150 mL in adults and 10-60 ml in neonates. There is a constant turnover of about 14% of the volume per hour. About 300-500 mL of CSF are formed per 24 hours (0.35 mL per minute).
CSF is obtained by lumbar puncture, with removal of fluid from the lumbar sac, located at the L3-4 or L4-5 interspace. At this level, the needle cannot injure