Components of the BBB

• Tight junctions between the capillary endothelial cells
• Continuous homogenous basement membrane
• Numerous astrocytic processes

Parts devoid of Blood Brain Barrier - circumventircular organs (CVO).

1. The pineal body
2. The subcommissural organ
3. The subfornical organ
4. The organum vasculosum of the lamina terminalis (supra-optic crest)
5. The median eminence
6. The neurohypophysis
7. The area postrema