fluid for the csf is derived from the bloodstream. the sites of csf formation are the
Cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found in the brain and spinal cord. It is produced in the choroid plexuses of the ventricles of the brain, and absorbed in the arachnoid granulations. There is about 125mL of CSF at any one time, and about 500mL is generated every day. CSF acts as a cushion or buffer for the brain, providing basic mechanical and immunological protection to the brain inside the skull. CSF also serves a vital function in cerebral autoregulation of cerebral blood flow.
Acid–base homeostasis The pH of the extracellular fluid, including the blood plasma, is normally tightly regulated between 7.36 and 7.42, by the chemical buffers, the respiratory system, and the renal system.[6][13][14][15]