cerebrospinalflüssigkeitsgefüllter

Cerebrospinal fluid (CSF) is a clear, colorless fluid that surrounds the brain and spinal cord, forming part of the central nervous system. It provides mechanical protection by cushioning neural tissue, reduces the brain’s effective weight through buoyancy, and helps maintain a stable chemical environment for neural signaling. CSF also participates in the exchange of nutrients and waste between the blood and neural tissue.

Most CSF is produced by the choroid plexus within the brain’s ventricles, with an average daily production of about 500 milliliters in adults. The fluid circulates from the lateral ventricles through the foramen of Monro to the third ventricle, then via the aqueduct of Sylvius to the fourth ventricle, and into the subarachnoid space surrounding the brain and spinal cord. It is gradually absorbed into the bloodstream through arachnoid granulations in the dural venous sinuses. The total CSF volume is normally about 125 to 150 milliliters.

Compositionally, CSF is relatively low in protein and cells compared with plasma. Normal CSF is clear and colorless, with glucose typically about two-thirds of blood glucose and a pH around 7.3. Abnormal CSF findings—such as elevated white cells, increased protein, decreased glucose, or the presence of blood—can indicate conditions including meningitis, subarachnoid hemorrhage, or inflammatory diseases. CSF analysis via lumbar puncture is a common diagnostic tool, and disturbances in CSF dynamics can contribute to hydrocephalus if production and absorption become imbalanced.