ABSTRACT
References .......................................................................................................................... 589
All organisms with a well-developed central nervous system (CNS) have a blood-brain
barrier (BBB). In all mammals the BBB is created by the endothelial cells forming the
capillaries of the brain and spinal cord microvasculature. The combined surface area of
these microvessels constitutes by far the largest surface area for blood-brain exchange.
This surface area, depending on the anatomical region, is between 150 and 200 cm2=g of tissue giving a total area for exchange in the brain of 12-18 m2 for the average human
adult [1].
