cerebroespinal

Cerebroespinal fluid (CSF) is the clear, colorless liquid that surrounds the brain and spinal cord. It is produced mainly by the choroid plexus within the brain’s ventricles and is refreshed continuously, with about 500 milliliters generated each day. The total CSF volume in an adult is roughly 125 to 150 milliliters, and the fluid circulates to nourish and protect neural tissue.

CSF follows a defined circulation pathway. It is secreted into the lateral ventricles, flows through the foramina of Monro into the third ventricle, passes via the cerebral aqueduct into the fourth ventricle, and then enters the subarachnoid space around the brain and spinal cord through the foramina of Luschka and Magendie. From there it is absorbed mainly into the venous system via arachnoid granulations, returning to the dural venous sinuses.

Functions of CSF include providing buoyant support to the brain, helping to maintain stable intracranial pressure, and offering chemical stability by maintaining ionic balance and pH. It also serves as a medium for the transport of nutrients, neurotrophic factors, and waste products, and participates in immune defense of the central nervous system.

Clinical relevance of CSF is broad. Impairment of production, flow, or absorption can lead to hydrocephalus, with accumulation of CSF and increased intracranial pressure. CSF analysis, often obtained by lumbar puncture, is used to diagnose infections such as meningitis, hemorrhage, and inflammatory or malignant conditions. Routine CSF tests assess opening pressure, color and clarity, cell counts, protein and glucose levels, and microbiological cultures.