<Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> The meninges (/ məˈnɪndʒiːz /, singular: meninx (/ ˈmiːnɪŋks / or / ˈmɛnɪŋks /), from Ancient Greek: μῆνιγξ, translit . mēninx, lit .' membrane', adjectival: meningeal / məˈnɪndʒəl /) are the three membranes that envelop the brain and spinal cord . In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater . Cerebrospinal fluid is located in the subarachnoid space between the arachnoid mater and the pia mater . The primary function of the meninges is to protect the central nervous system . </P> <P> The dura mater (Latin: tough mother) (also rarely called meninx fibrosa or pachymeninx) is a thick, durable membrane, closest to the skull and vertebrae . The dura mater, the outermost part, is a loosely arranged, fibroelastic layer of cells, characterized by multiple interdigitating cell processes, no extracellular collagen, and significant extracellular spaces . The middle region is a mostly fibrous portion . It consists of two layers: the endosteal layer, which lies closest to the calvaria (skullcap), and the inner meningeal layer, which lies closer to the brain . It contains larger blood vessels that split into the capillaries in the pia mater . It is composed of dense fibrous tissue, and its inner surface is covered by flattened cells like those present on the surfaces of the pia mater and arachnoid mater . The dura mater is a sac that envelops the arachnoid mater and surrounds and supports the large dural sinuses carrying blood from the brain toward the heart . </P> <P> The dura has four areas of infolding: </P>

Which layer of the meninges is closest to the skull bone