The cerebrospinal fluid (CSF) is a colorless, transparent fluid produced from the arterial flow of blood by the choroid plexuses found within the ventricular system of the brain. The CSF exits the ventricular system and enters the subarachnoid space and its cisterns. It is then absorbed at the level of the arachnoid granulations into the venous component of the cardiovascular system.

The CSF has many functions, some of them being protection, the creation of a fluid environment where the brain 'floats", cleansing, and others. For a more detailed description of the CSF, click here.

The CSF is produced at an average rate of 550-700ml/day. It is absorbed at the same rate. An imbalance between production and absorption of CSF (as well as a blockage within the ventricular system) can lead to an accumulation of CSF within the brain, causing hydrocephalus.