Arachnoid mater

Definition

The arachnoid mater is a delicate, web-like middle layer of the meninges that covers and protects the brain and spinal cord. It lies between the dura mater and pia mater.

5 Must Know Facts For Your Next Test

1. The arachnoid mater is part of the three-layered meninges that protect the central nervous system.
2. Cerebrospinal fluid flows in the subarachnoid space, which is located between the arachnoid mater and pia mater.
3. Arachnoid granulations allow cerebrospinal fluid to drain back into the bloodstream.
4. Inflammation of the arachnoid mater, often caused by infection, is known as arachnoiditis.
5. It plays a critical role in cushioning the brain and spinal cord from trauma.

Review Questions

• What are the primary functions of the arachnoid mater?
• Where is cerebrospinal fluid located in relation to the arachnoid mater?
• What condition results from inflammation of the arachnoid mater?

Related terms

dura mater: The outermost, tough layer of the meninges.

pia mater: The innermost layer of the meninges that closely adheres to the surface of the brain and spinal cord.

meningitis: An infection or inflammation of the protective membranes covering the brain and spinal cord.