Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
The pia mater is the delicate innermost layer of the meninges, which are the protective membranes that envelop the brain and spinal cord. It closely adheres to the surface of the central nervous system, following its contours and blood vessels.
The three layers of protective tissue that cover the brain and spinal cord, consisting of the dura mater, arachnoid mater, and pia mater.
Cerebrospinal Fluid (CSF): A clear fluid that circulates in the space between the arachnoid mater and pia mater (subarachnoid space), cushioning and protecting the brain and spinal cord.
Brain Barrier - A selective permeability barrier formed by endothelial cells that prevents most substances in the blood from entering the brain, ensuring a stable environment for neural activity