The dura mater is a firm connective tissue, containing blood vessels, which covers the brain and spinal cord of vertebrates but is separated from them by a small space. The dura mater (Latin for "tough mother") is the toughest, outermost envelope enclosing the central nervous system, and the most fibrous of the three protective membranes or meninges. The other meninges are the arachnoid and the pia mater.