which layer of the meninges is connected to the brain
pia mater The pia mater
title: Meninges text: Meninges The meninges (, "singular:" meninx ( or ), from , "adjectival:" meningeal ) 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. The dura mater () (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 title: Meninges text: inner surface toward the innermost collagenous portion of the arachnoid reticular layer. The pia mater () is a very delicate membrane. It is the meningeal envelope that firmly adheres to the surface of the brain and spinal cord, following all of the brain's contours (the gyri and sulci). It is a very thin membrane composed of fibrous tissue covered on its outer surface by a sheet of flat cells thought to be impermeable to fluid. The pia mater is pierced by blood vessels to the brain and spinal cord, and its capillaries nourish the brain. The arachnoid and pia mater title: Meninges text: 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 title: Meninges text: the same animals, Sterzi demonstrated that, while in the spinal medulla the dura keeps its identity, in the skull it fuses with the periosteum. He also demonstrated the continuity of all meninges with the envelopes of nerves and with the filum terminale. Mammals (as higher vertebrates) retain the dura mater, and the secondary meninx divides into the arachnoid and pia mater. Meninges The meninges (, "singular:" meninx ( or ), from , "adjectival:" meningeal ) 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 title: Meninges text: sac that envelops the arachnoid mater and surrounds and supports the large dural sinuses carrying blood from the brain toward the heart. The dura has four areas of infolding: The middle element of the meninges is the arachnoid mater, so named because of its spider web-like appearance. It cushions the central nervous system. This thin, transparent membrane is composed of fibrous tissue and, like the pia mater, is covered by flat cells also thought to be impermeable to fluid. The shape of the arachnoid does not follow the convolutions of the surface of the brain and so looks like a