The |brain| and |spinal cord| are covered by three protecting membranes, or meninges. These are the |dura mater|, the |pia mater|, and the arachnoid. The innermost of these membranes is the thin, compact |pia mater| which carries ~blood~ vessels which supply the central nervous system. The intermediate layer is the arachnoid, so called because it resembles a spider's web. The outer meningeal membrane is the |dura mater|, a tough, durable layer of connective tissue which protects the layers beneath from the bones surrounding them. The space between the |pia mater| and arachnoid is called the subarachnoid space and the space between the arachnoid and the |dura mater| is called the subdural space. Inflammation of these membranes is a condition called ~meningitis~.
