Figure 32-5. Blood—CSF barrier.

Figure 32-5

Blood—CSF barrier. The capillaries in the choroid plexus differ from those of the brain in that there is free movement of molecules across the endothelial cell through fenestrations and intercellular gaps. The blood—CSF barrier is at the choroid plexus epithelial cells, which are joined together by tight junctions. Microvilli are present on the CSF-facing surface. These greatly increase the surface area of the apical membrane and may aid in fluid secretion. Diffusion, facilitated diffusion and active transport into CSF, as well as active transport of metabolites from CSF to blood, have been demonstrated in the choroid plexus.

From: Blood—Cerebrospinal Fluid Barrier

Cover of Basic Neurochemistry
Basic Neurochemistry: Molecular, Cellular and Medical Aspects. 6th edition.
Siegel GJ, Agranoff BW, Albers RW, et al., editors.
Philadelphia: Lippincott-Raven; 1999.
Copyright © 1999, American Society for Neurochemistry.

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