Cellular and Molecular Biology

Free Version

Upgrade subject to access all content


Blood Brain Barrier


The blood brain barrier (BBB) protects the brain from harmful chemicals.

cells are directly responsible for forming the blood brain barrier (BBB).

There are

junctions between these cells that prevent large molecules from passing into neural tissue.

Other cells that help to form the BBB are

; these cells have

that project to and contact blood vessels.

The BBB is not impenetrable to all molecules. Small molecules such as

can pass freely through the BBB.