Which delicate, innermost layer completely lines the brain and its contours containing networks of capillaries?

Which delicate, innermost layer completely lines the brain and its contours containing networks of capillaries?

• A. Pia mater
• B. Grey Matter
• C. Dura mater
• D. Arachnoid mater

Answer: (A)

The innermost, delicate layer that tightly covers the brain and follows every contour is the pia mater. It lies directly on the brain surface, dipping into sulci and wrapping around gyri, and it contains a rich network of capillaries that supply blood to the brain tissue. The other membranes serve different roles: the dura mater is the tough outer protective layer, and the arachnoid mater sits between the dura and pia and meshes with the subarachnoid space where cerebrospinal fluid flows. Grey matter is actual brain tissue, not a covering.

The innermost, delicate layer that tightly covers the brain and follows every contour is the pia mater. It lies directly on the brain surface, dipping into sulci and wrapping around gyri, and it contains a rich network of capillaries that supply blood to the brain tissue.

The other membranes serve different roles: the dura mater is the tough outer protective layer, and the arachnoid mater sits between the dura and pia and meshes with the subarachnoid space where cerebrospinal fluid flows. Grey matter is actual brain tissue, not a covering.