Meninges

Definition

Meninges are three protective membranes that envelop the brain and spinal cord. They consist of the dura mater, arachnoid mater, and pia mater.

5 Must Know Facts For Your Next Test

1. The meninges provide a protective barrier against infections and physical impacts to the central nervous system.
2. Meningitis is an inflammation of the meninges usually caused by bacterial or viral infections.
3. The dura mater is the outermost layer, providing strong protection and containing larger blood vessels.
4. The arachnoid mater is the middle layer, with a web-like structure, allowing cerebrospinal fluid (CSF) to flow underneath it in the subarachnoid space.
5. The pia mater is the innermost layer, closely adhering to the surface of the brain and spinal cord.

Review Questions

• What are the three layers of the meninges?
• How do the meninges protect the central nervous system from infections?
• Which layer of meninges contains cerebrospinal fluid?

Related terms

Cerebrospinal Fluid:

A clear fluid found in the brain and spinal cord that cushions these organs.

Meningitis:

An inflammation of the meninges usually caused by infection.

Blood-Brain Barrier:

A selective permeability barrier that protects the brain from harmful substances in blood circulation.