Search results
Results from the WOW.Com Content Network
The middle region is a mostly fibrous portion. It consists of two layers: the endosteal layer, which lies closest to the skull, and the inner meningeal layer, which lies closer to the brain. [7] 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 ...
Disabling neuropsychological effects are seen in up to half of bacterial meningitis survivors. Research into how bacteria invade and enter the meningeal layers is the next step in prevention of the progression of meningitis. [17] A tumor growing from the meninges is referred to as a meningioma. Most meningiomas grow from the arachnoid mater ...
The arachnoid mater is interposed between the two other meninges, the more superficial (closer to the surface) and much thicker dura mater and the deeper pia mater, from which it is separated by the subarachnoid space. The delicate arachnoid layer is not attached to the inside of the dura but against it, and surrounds the brain and spinal cord.
In the brain a laminar organization is evident in the arrangement of the three meninges, the membranes that cover the brain and spinal cord. These membranes are the dura mater, arachnoid mater, and pia mater. The dura mater has two layers a periosteal layer near to the bone of the skull, and a meningeal layer next to the other meninges. [3]
The dura mater covering the spinal cord is known as the dural sac or thecal sac, and only has one layer (the meningeal layer) unlike cranial dura mater. The potential space between these two layers is known as the epidural space, [5] which can accumulate blood in the case of traumatic laceration to the meningeal arteries.
Embryologically, the arachnoid trabeculae are the remnants of the common precursor that forms both the arachnoid and pial layers of the meninges. The initial development of the subarachnoid space occurs in two phases: [13] A mesenchymal layer "invades" between the embryonic epithelium and the developing neuroepithelium of the telencephalon.
The findings from a post mortem are usually a widespread inflammation of the pia mater and arachnoid layers of the meninges. Neutrophil granulocytes tend to have migrated to the cerebrospinal fluid and the base of the brain, along with cranial nerves and the spinal cord, may be surrounded with pus – as may the meningeal vessels. [57]
In the skull, the periosteal layer of the dura mater adheres to the inner surface of the skull bones while the meningeal layer lays over the arachnoid mater. Between them is the epidural space . The two layers of the dura mater separate at several places, with the meningeal layer projecting deeper into the brain parenchyma forming fibrous septa ...