Crossword clues for arachnoid
The Collaborative International Dictionary
Arachnoid \A*rach"noid\, a. [Gr. ? like a cobweb; ? spider, spider's web + e'i^dos form.]
Resembling a spider's web; cobweblike.
(Anat.) Pertaining to a thin membrane of the brain and spinal cord, between the dura mater and pia mater.
(Bot.) Covered with, or composed of, soft, loose hairs or fibers, so as to resemble a cobweb; cobwebby.
Arachnoid \A*rach"noid\, n.
(Anat.) The arachnoid membrane.
(Zo["o]l.) One of the Arachnoidea.
Douglas Harper's Etymology Dictionary
"cobweb-like," especially of the membrane around the brain and spinal cord, 1789, from Modern Latin arachnoides, from Greek arakhnoeides "cobweb-like," from arakhne "cobweb" (see arachnid) + -oeides (see -oid).
Wiktionary
a. 1 Relating to spiders. 2 Relating to or resembling spider webs. 3 (context anatomy English) Relating to the arachnoid mater, the middle layer of the meninges, the three membranes that protect the brain. n. 1 (context biology English) An arachnid 2 (context physiology English) The arachnoid mater, the middle layer of the meninges, the three membranes that protect the brain 3 (context astronomy English) A round network of fractures in the crust of Venus
WordNet
adj. relating to or resembling a member of the class Arachnida [syn: arachnidian, spidery, spiderlike, spiderly]
n. the middle of the 3 meninges [syn: arachnoid membrane]
air-breathing arthropods characterized by simple eyes and four pairs of legs [syn: arachnid]
Wikipedia
Arachnoid may refer to:
- Relating to arachnids
- Arachnoid mater, a layer of the meninges, membranes that contain the central nervous system
- Arachnoid granulation, small protrusions of the arachnoid mater
- Arachnoid (astrogeology), a geological structure found only on the planet Venus
- Arachnoid (botany), referring to organs with a cobwebby exterior appearance
In astrogeology, an arachnoid is a large structure of unknown origin, and they have been found only on the surface of the planet Venus. Arachnoids get their name from their resemblance to spider webs. They appear as concentric ovals surrounded by a complex network of fractures, and can span 200 kilometers. Over thirty arachnoids have been identified on Venus, so far. The arachnoid might be a strange relative to the volcano, but possibly different arachnoids are formed by different processes.
Arachnoid as a descriptive term in botany, refers to organs such as leaves or stems that have a cobwebby exterior appearance, from being covered with fine white hairs, usually tangled. Such material is one common cause of plants having a grey or white appearance. The usages of various authors in distinguishing between "arachnoid" and a few other terms referring to hairiness, such as floccose, pubescent, tomentum, cottony, or villous, tend to be arbitrary, but as a rule the term is best reserved for hairiness lighter than a felted layer, and inclined to rub off or to be easily damaged in other ways. The arachnoid appearance is common on the leaves and stems of various sclerophyllous members of the Asteraceae, such as some thistles.
Nonetheless, "cobwebbiness" is a subjective impression, and in the likes of Hayworthia arachnoidea the arachnoid impression arises from the thicket of spinescent leaf denticles that are not at all fine, tangled, or fragile. In the cactus Cephalocereus senilis, the arachnoid effect arises from long-lasting hairy spines.
Usage examples of "arachnoid".
The tentacles of the ichthyoid were specialized for large-scale manipulation, those of the arachnoid for minute work.
On the whole the arachnoid partners dominated in manual skill, experimental science, the plastic arts, and practical social organization.
Every arachnoid still emerged for sexual mating, and also for certain ritual gymnastic exercises.
Not only in experience of electrical engineering but also in native practical ability they were eclipsed by their arachnoid partners.
The directorate of extra-marine activities demanded a much increased arachnoid population.
While every healthy arachnoid longed to take part in the adventurous new life, he or she longed also, through sheer affection and symbiotic entanglement, to assist his or her ichthyoid mate to have an equal share in that life.
At this time the symbiotic race consisted of an immense host of arachnoid adventurers scattered over many planets, and a company of some fifty thousand million super-ichthyoids living a life of natatory delight and intense mental activity in the ocean of their great native world.
Several of these included worlds which, when the early Arachnoid explorers visited them telepathically, were found to be inhabited by native races of pre-utopian rank.
Several of these included worlds which, when the early Arachnoid explorers visited them tele- pathically, were found to be inhabited by native races of pre-utopian rank.
Perched on the windscreen beside some leaves is a furry, bird-sized, brightly colored arachnoid, a sort of flying spider.
Thus, one layer of the arachnoid envelopes the brain and spinal cord, and the other lines the dura mater.
The space between the internal and the external layers of the arachnoid membrane of the brain is much smaller than that enclosed by the corresponding layers of the arachnoid membrane of the spinal column.
Finally, within the spaces of the arachnoid is a lymph-like liquid which completely envelops the brain and the cord, and which, by serving as a watery cushion, protects them from jars and shocks.
The creature remained perched there like some arachnoid gargoyle watching me from the roof of a church.
At the autopsy are found hyperemia of the arachnoid, and slight chronic leptomeningitis and pachymeningitis.