Circulation of Cerebrospinal Fluid (CSF)

Circulation of cerebrospinal fluid (CSF) is a clear, colorless liquid that circulates between the ventricular system and the subarachnoid space. In addition to its function as a natural cushion for the brain, CSF provides the circulation of metabolic products, hormones, and neurotransmitters. Moreover, it has tasks such as maintaining the homeostatic balance of the central nervous system, protecting the brain against mechanical injuries, preventing direct contact of the brain with the extracellular region. It also has a role in maintaining cerebral interstitial fluid (ISF) homeostasis and neuronal regulation. Normal CSF production, its circulation, and absorption have a critical role for the development and functioning of the brain. In an average adult person, roughly 150 ml of CSF circulates at any given moment. The ventricular part accounts for about 17% of the total volume of fluid, with the rest located in the subarachnoid cisterns and space. CSF is produced at a rate of about 0.3–0.4 mL/min, translating to 18–25 mL/H and 430–530 mL/day.