Search results
Results from the WOW.Com Content Network
The arachnoid mater covering the brain is referred to as the arachnoidea encephali, and the portion covering the spinal cord as the arachnoidea spinalis. The arachnoid and pia mater are sometimes considered as a single structure, the leptomeninx, or the plural version, leptomeninges (lepto, from the Greek root meaning "thin" or "slender").
The middle element of the meninges is the arachnoid mater, or arachnoid membrane, so named because of its resemblance to a spider web. It cushions the central nervous system. This thin, transparent membrane is composed of fibrous tissue and, like the pia mater, has an outer layer of tightly packed flat cells, forming the arachnoid barrier. [8]
Arachnoiditis is an inflammatory condition of the arachnoid mater or 'arachnoid', one of the membranes known as meninges that surround and protect the central nervous system. The outermost layer of the meninges is the dura mater (Latin for hard) and adheres to inner surface of the skull and vertebrae. [ 1 ]
Arachnoid (astrogeology), a geological structure found only on the planet Venus; Arachnoid (botany), referring to organs with a cobwebby exterior appearance; Arachnoid granulation, small protrusions of the arachnoid mater; Arachnoid mater, a layer of the meninges, membranes that contain the central nervous system
This results in fluid-filled cavities with random spacing and size. The mesenchymal material between these cavities is the origin of the arachnoid trabeculae. The upper and lower surfaces of the layer become the arachnoid and pia mater membranes, to which the trabecular structure remains attached.
The brain and spinal cord are covered by the meninges, the three protective membranes of the tough dura mater, the arachnoid mater and the pia mater. The cerebrospinal fluid (CSF) within the skull and spine provides further protection and also buoyancy, and is found in the subarachnoid space between the pia mater and the arachnoid mater.
The anatomy term "epidural space" has its origin in the Ancient Greek language; ἐπί, "on, upon" + dura mater also known as "epidural cavity", "extradural space" or "peridural space". In humans the epidural space contains lymphatics , spinal nerve roots, loose connective tissue , adipose tissue , small arteries , dural venous sinuses and a ...
The arachnoid membrane and the dura mater exist in flush contact with one another in the living person's spine due to fluid pressure from CSF in the subarachnoid space pushing the arachnoid membrane out towards the dura. Therefore, once the needle has pierced the dura mater it has also traversed the thinner arachnoid membrane.