The Blood-Brain Barrier

Hover over the different parts of the diagram to learn more.

Astrocyte
Astrocyte
Foot
Processes
neuron
Neuron
basement membrane
Basement Membrane
Red Blood Cells
Pericyte
Axon
Astrocytes are connected to neurons and endothelial cells via foot processes.
Active Barrier active barrier
Active Barrier
Active blood-brain barrier function is based on the interplay between:
influx transporterInflux Transporters
which supply the brain with glucose, amino acides, and other nutrients.
metabolizing enzymeMetabolizing Enzymes
are thought to form a second line of defense by degrading xenobiotics entering the brain.
efflux transporterEfflux Transporters
which limit access of xenobiotics (including therapeutic drugs) into the brain and clear waste products out of the brain
endothelial cells
Endothelial Cells
form brain capillaries that comprise the blood-brain barrier.
tight junctions
Tight Junctions
sealing neighboring endothelial cells to form a passive, physical barrier that restricts free diffusion of molecules into and out of the brain.