arachnoid


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

a·rach·noid

 (ə-răk′noid′)
adj.
1. Anatomy Of or relating to a delicate membrane enclosing the spinal cord and brain.
2. Of, relating to, or resembling arachnids.
3. Covered with or consisting of thin, soft, entangled hairs or fibers resembling those of a cobweb or spider's web.
n.
1. An arachnid.
2. Anatomy A delicate membrane that encloses the spinal cord and brain and lies between the pia mater and dura mater.

[New Latin arachnoīdēs, from Greek arakhnoeidēs, cobweblike : arakhnē, spider + -oeidēs, -oid.]

arachnoid

(əˈræknɔɪd)
n
1. (Anatomy) the middle of the three membranes that cover the brain and spinal cord. See meninges
2. (Zoology) another name for arachnid
adj
3. (Anatomy) of or relating to the middle of the three meninges
4. (Botany) botany consisting of or covered with soft fine hairs or fibres
5. (Zoology) of or relating to the arachnids

a•rach•noid

(əˈræk nɔɪd)

adj.
1. of or belonging to the arachnids.
2. of or pertaining to the arachnoid.
3. Bot. formed of or covered with long, delicate hairs or fibers.
n.
4. the serous membrane forming the middle of the three coverings of the brain and spinal cord. Compare dura mater, meninges, pia mater.
[1745–55; < New Latin arachnoīdes < Greek arachnoeidḗs cobweblike. See arachnid, -oid]

arachnoid

A web-like membrane: the middle of the three meninges covering the brain and spinal cord.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.arachnoid - the middle of the 3 meninges
meninges, meninx - a membrane (one of 3) that envelops the brain and spinal cord
leptomeninges - the two innermost layers of the meninges; cerebrospinal fluid circulates between these innermost layers
2.arachnoid - air-breathing arthropods characterized by simple eyes and four pairs of legsarachnoid - air-breathing arthropods characterized by simple eyes and four pairs of legs
arthropod - invertebrate having jointed limbs and a segmented body with an exoskeleton made of chitin
Arachnida, class Arachnida - a large class of arthropods including spiders and ticks and scorpions and daddy longlegs; have four pairs of walking legs and no wings
harvestman, Phalangium opilio, daddy longlegs - spiderlike arachnid with a small rounded body and very long thin legs
scorpion - arachnid of warm dry regions having a long segmented tail ending in a venomous stinger
false scorpion, pseudoscorpion - small nonvenomous arachnid resembling a tailless scorpion
whip scorpion, whip-scorpion - nonvenomous arachnid that resembles a scorpion and that has a long thin tail without a stinger
spider - predatory arachnid with eight legs, two poison fangs, two feelers, and usually two silk-spinning organs at the back end of the body; they spin silk to make cocoons for eggs or traps for prey
acarine - mite or tick
Adj.1.arachnoid - relating to or resembling a member of the class Arachnidaarachnoid - relating to or resembling a member of the class Arachnida
zoological science, zoology - the branch of biology that studies animals
Translations

a·rach·noid

n. aracnoides, membrana media cerebral que cubre el cerebro y la médula espinal.
References in periodicals archive ?
Nonneoplastic lesions diagnosed were 8 cases of abscess and 3 cystic lesions diagnosed as arachnoid cyst.
Other lesions include fungal infections, pituitary adenoma, schwannoma, neurofibroma, carotid body paraganglioma, craniopharyngioma, arachnoid cyst, medulloblastoma and medulloepithelioma.
3% of cases it results in subdural hematoma, which is associated with direct interaction of the aneurysm with the basal arachnoid membrane.
Neonatal anterior cerivical arachnoid cyst: a case report and review of the literature.
1] They are extra-axial tumors arising from arachnoid cap cells.
Meningiomas are derived from the arachnoid cap cells, also called pacchionian bodies.
The subdural space has been classically described as a virtual space occupied by serous fluid contained between the dura mater and the arachnoid.
Meningioma can be found along any of the outer surface of the brain and in the ventricular system in which it arise from the stromal arachnoid cell of the choroid plexus.
Some authors presume that such meningiomas arise from arachnoid cells of the pia mater that stretches into the surface of brain or sulcus with perforating blood vessels, while others suggest that the arachnoid cells rest in the brain during the migration progress [3].