Answer
Cerebrospinal fluid is a clear fluid much like plasma but with much less proteins and a different concentrations and combinations of electrolyte sand other solute. The CSF is mainly probably 99% water but i besides nourishing and supplying oxygen the CSF also supports and cushions the brain and acts as an effective shock absorber. The buoyancy it gives the brain prevents the soft delicate tissues from being crushed against hard cranial bones surfaces--because if its own weight.
The amount of CSF produced per day by the choroid plexi is about 450 to 550 ml per person. However the cavities and spaces in the brain can accommodate only about 150 ml at any instant. Consequently, there must be a constant flow and reabsorption of CSF or fluid pressure would increase in the brain, This would serious inimical effects on the function of neurons that could lead to unconsciousness and even death
Work Step by Step
Increased amounts of fluid in the brain is called hydrocephalus. It is less dangerous for infants whose cranial bone sutures have not closed. In infants, the head enlarges to relieve the pressure. In adults with closed cranial bone suture there can be no head-swelling and the cranial pressure intensifies with much more serious long lasting brain damage.
Blockages may be caused by tumors, cysts, scarring, ad infections. Some symptoms are nausea, vomiting, loss of balance and coordination , lethargy, drowsiness, and impaired cognition.