Arachnoid mater

Definition

The arachnoid mater is the middle layer of the three meninges that surround and protect the brain and spinal cord. It is named for its spider web-like appearance due to its fine, thread-like fibers.

5 Must Know Facts For Your Next Test

1. The arachnoid mater lies between the dura mater and pia mater.
2. It contains the subarachnoid space, which is filled with cerebrospinal fluid (CSF).
3. Arachnoid villi are structures in the arachnoid mater that help absorb CSF into the bloodstream.
4. It provides a cushioning effect for the central nervous system.
5. The arachnoid barrier contributes to the blood-brain barrier, regulating substances entering the brain.

Review Questions

• Where is the arachnoid mater located in relation to other meninges?
• What fluid is contained within the subarachnoid space?
• What role do arachnoid villi play in cerebrospinal fluid dynamics?

Related terms

dura_mater: The outermost and toughest layer of the meninges, providing strong protection for the brain and spinal cord.

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

cerebrospinal_fluid: A clear, colorless body fluid found within the subarachnoid space that cushions and protects neural tissues.