What three layers of membranes cover and protect the brain spinal cord?

The brain and spinal cord are covered and protected by three layers of membranes known as the meninges. From the outermost layer to the innermost layer, these membranes are:

1. Dura Mater: The dura mater is the toughest and outermost layer of the meninges. It is a thick, fibrous membrane that lines the inner surface of the skull and the vertebral canal. The dura mater provides structural support and protection for the brain and spinal cord.

2. Arachnoid Mater: The arachnoid mater is a delicate, web-like membrane located between the dura mater and the pia mater. It is separated from the dura mater by a fluid-filled space called the subdural space. The arachnoid mater helps to cushion and protect the brain and spinal cord.

3. Pia Mater: The pia mater is the innermost layer of the meninges. It is a thin, highly vascularized membrane that closely follows the contours of the brain and spinal cord. The pia mater provides nutrients and oxygen to the brain and spinal cord, and it also helps to drain away waste products.

Together, the dura mater, arachnoid mater, and pia mater form a protective barrier that surrounds and protects the brain and spinal cord.