Dura mater -the dura mater (tough mother) contains the venous sinuses and is composed of dense connective tissue and possesses very limited osteogenic potential. the dura mater is one of the three protective layers that comprise the meninges surrounding the brain and spinal cord. in the spinal cord, the dura is separated from the periosteum by the epidural space. the thin subdural space lies between the dura mater and the arachnoid. the arachnoid is composed of a weblike avascular connective tissue that forms villi for the reabsorption of cerebrospinal fluid (csf) into the venous sinuses found in the dura. the subarachnoid space contains the csf, which is formed both by ultrafiltration of the blood and transport across the epithelial lining of the choroid plexuses. the pia covers the brain and spinal cord as a delicate, vascular connective tissue. it lines the perivascular spaces through which blood vessels penetrate the cns. the periosteum is an important connective tissue layer surrounding the bone of the skull. this layer retains osteogenic potential even in the adult.
