Ventricles

Ventricles are interconnected by aqueducts and wall openings

Blockage in the central canal or fourth ventricle can lead to hydrocephalus (enlarging ventricles) and may require an external shunt for treatment

Cerebrospinal Fluid (CSF)

•Similar to serum, but most protein removed

•Bathes brain and spinal cord

•Protective cushion around CNS

•Choroid plexuses produce CSF which fills ventricles and other parts of brain and spinal cord

–Composed of ependymal cells, their support tissue, and associated blood vessels

–Blood-cerebrospinal fluid barrier

•Endothelial cells of capillaries attached by tight junctions

•Substances do not pass between cells

•Substances must pass through cells

•Makes the barrier very selective