Question

what is the innermost meninx that protects the brain and spinal cord?

Explanation:

The meninges are three layers of protective tissue (the dura mater, arachnoid mater, and pia mater) that surround the brain and spinal cord. The pia mater is the innermost layer, closely adhering to the surface of the brain and spinal cord, following their contours and providing a delicate protective covering.

Answer:

The innermost meninx that protects the brain and spinal cord is the pia mater.