arachnoid


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.

arachnoid

[ə′rak‚nȯid]
(anatomy)
A membrane that covers the brain and spinal cord and lies between the pia mater and dura mater.
(botany)
Of cobweblike appearance, caused by fine white hairs. Also known as araneose.
(invertebrate zoology)
Any invertebrate related to or resembling the Arachnida.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Arachnoid involvement was observed 10% and 40% of the sections in the treatment and control groups, respectively.
Suprasellar arachnoid cyst: a 20- year follow-up after stereotactic internal drainage: case report and review of the literature.
Included patients having traumatic deformity of the spine, patients having any congenital anomaly of spine, patients undergoing emergency lower body surgeries, patients having any contraindication to sub arachnoid block e.g.
(3) Pathologic evaluation for type 2 cysts may reveal arachnoid or glial-ependymal cells.
They are thought to be derived from endothelial cells of obliterated vessels or may be formed by the secretion of arachnoid vessel cells and the calcification of necrotic cells (10).
These arachnoid villi and granulations are blocked after dural sinus thrombosis leading to the development of papilledema and intracranial hypertension.2 Various invasive and non-invasive imaging tools are available to assess the venous system.
It was diagnosed as a posterior fossa arachnoid cyst causing a mild mass effect.
Microscopically, the cyst wall contained fibrocollagenous tissue and was lined by a single layer of uniform flat cells, suggestive of arachnoid cyst.
Arachnoid cysts are CSF containing cysts lined by a layer of flattened mature arachnoid cells caused by maldevelopment of meninges.
In that study; among mild ventricular enlargement group 7 of 39 and among moderate ventricular enlargement group all five children had other significant accompanying abnormalities.13 Within our study group half of the cases had abnormality like cerebral atrophy, porencephalic cyst, arachnoid cyst or pachygyria (Table-I).
Virchow is the first one to describe sand-like granulations in these meningothelial proliferations and had named them "psammoma body", in 1863 [33], while Bailey and Bucy had demonstrated their origin from the arachnoid cap cells [34].
Cranial MRI scan showed mildly dilated lateral and third ventricles, and there was a 17x13 mm arachnoid cyst at the velum interpositum (Figure 6).