Pia mater:

a close-up view of the meninges.

a close-up view of the meninges.

the innermost layer of the meninges, the pia mater closely covers the brain. It acts as a barrier and aids in the production of cerebrospinal fluid.

Read more: Know your brain - Meninges

Watch this 2-Minute Neuroscience video to learn more about the meninges.