arachnoid

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Related to arachnoid membrane: meninges, arachnoid cyst

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 ?
Researchers believe that most cases of arachnoid cysts are developmental malformations that arise from the unexplained splitting or tearing of the arachnoid membrane. According to the medical literature, cases of arachnoid cysts have run in families (Familial cases) suggesting that a genetic predisposition may play a role in the development of arachnoid cysts in some individuals.
[1,5,6] Successive small bleeding episodes may cause adhesion of the aneurysm to the adjacent arachnoid membrane, and the final rupture occurs into the subdural space.
For a lesion to be considered an arachnoid cyst, it must meet three criteria: (1) it must be enveloped by an arachnoid membrane, (2) it must contain arachnoidea mater cells, and (3) it must contain CSE (8,9) These requirements, by definition, ensure duplication of the arachnoid membrane, leading to a distinct cyst.
The segmentally hypertrophied arachnoid membrane provides a cause for the hydrocephalus and corresponding cerebral atrophy.
(2-6) Kumar et al (2) postulated that these tumors arise from meningoepithelial cells, which are present throughout the arachnoid membrane with more concentration at the arachnoid villi within the dural venous sinuses.
The outside is called the dura mater; the middle, the arachnoid membrane; and the innermost, the pia mater.
projections of the arachnoid membrane equipped with one way valves).[9]