What is the function of the meninges?

• A. They regulate blood flow to the brain
• B. They protect the brain and spinal cord
• C. They produce CSF
• D. They protect the brain and spinal cord; layers from outer to inner are dura mater, arachnoid mater, and pia mater

Answer: (D)

Meninges mainly serve to protect the brain and spinal cord, forming a protective barrier around the CNS. They consist of three layers in order from outer to inner: dura mater, arachnoid mater, and pia mater. The dura is the tough outer layer, the arachnoid is a loose, web-like middle layer, and the pia mater is a delicate layer that adheres closely to the brain’s surface. The spaces between these layers help cushion the CNS and contain CSF, though CSF itself is produced by the choroid plexus in the ventricles, not by the meninges. So the statement that they protect the brain and spinal cord and correctly names the outer-to-inner layers best captures both their function and anatomy.