Cerebrospinal Fluid  
     ..(CSF)
     .. Is a clear, colorless body fluid- 
     ..bathes the-     Brain
                     Spinal cord
    Formed and Secreted by the choroid - 
    plexus, special tissue that has many 
    blood vessels and lines the small 
     .. cavities (ventricles) in the  brain
  It is continually produced, - 
  circulated, and then absorbed into the 
  ..blood system
  .About 500 mL is produced each day - 
  This rate of production means that  
  all of the CSF is replaced every few 
  ..hours
..The primary function of CSF is to
    :Buoyancy
   The actual mass of the human brain is 
   ; about 1400 grams
   however, the net weight of the brain 
   suspended in the CSF is equivalent to 
   . a mass of 25 grams
   which allows the brain to maintain 
   its density without being impaired by its 
    own weight
  Protection: CSF protects the brain tissue 
  . from injury
  Chemical stability: CSF maintain the 
  distribution of necessary substance and 
  waste product between CNS and Blood 
   stream
  Prevention of brain ischemia: made by decreasing 
  the amount of CSF in the limited space inside 
  the skull. This decreases total  pressure  and