(7) Blood Brain Barrier | Blood Brain Barrier - Structure & Function | Blood CSF barrier

The Blood-Brain Barrier (BBB) is a selective permeability barrier that protects the brain from harmful substances while allowing essential nutrients to pass through. It is primarily composed of endothelial cells that are tightly joined together, forming a physical barrier, along with astrocytes and pericytes that support its function. In contrast, the Blood-Cerebrospinal Fluid (CSF) barrier regulates the exchange between the blood and the CSF, ensuring the brain's environment remains stable.