Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates.
The cerebrospinal fluid circulates in the subarachnoid space around the brain and spinal cord, and in the ventricles of the brain.
Vials containing human cerebrospinal fluid
In cell biology, extracellular fluid (ECF) denotes all body fluid outside the cells of any multicellular organism. Total body water in healthy adults is about 50–60% of total body weight; women and the obese typically have a lower percentage than lean men. Extracellular fluid makes up about one-third of body fluid, the remaining two-thirds is intracellular fluid within cells. The main component of the extracellular fluid is the interstitial fluid that surrounds cells.
The distribution of the total body water in mammals between the intracellular compartment and the extracellular compartment, which is, in turn, subdivided into interstitial fluid and smaller components, such as the blood plasma, the cerebrospinal fluid and lymph