The meninges are three layers of tough, membrane-like tissue that surround and protect the brain and spinal cord. These three layers are, from outermost to innermost:

• Dura mater (tough mother)
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  Dura mater brain
• Arachnoid mater (spider web mother)
• Pia mater (tender mother)
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  Pia mater brain

The pia mater is the innermost layer of the meninges. It is a thin, delicate membrane that closely follows the contours of the brain and spinal cord. The pia mater contains many blood vessels that supply the brain and spinal cord with nutrients. It also helps to anchor the brain and spinal cord to the skull and bones of the spine.

The dura mater is the outermost layer of the meninges. It is a tough, fibrous membrane that provides structural support and protection for the brain and spinal cord. The dura mater also contains sinuses, which are large channels that drain blood from the brain.