Seta
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2008-06-04T10:20:39Z
Jwelby
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/* Animal setae */
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{{wiktionary|seta}}
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'''Seta''' (plural: '''setae''') is a [[biology|biological]] term derived from the [[Latin]] word for "[[bristle]]". It refers to a number of different bristle- or hair-like structures on living [[organism]]s.
==Animal setae==
[[Image:Setae.png|thumb|Setae on the toes of an ''[[Uroplatus]]'' [[gecko]]]]
In [[zoology]], most "setae" occur in [[invertebrates]].
*Setae in [[annelid]]s are stiff bristles present on the body. They help for example [[earthworm]]s to attach to the surface and prevent backsliding during [[peristaltic]] motion. These hairs are what make it difficult to pull a worm straight from the ground. Setae in [[polychaetes]] (a group including earthworms) are largely composed of [[chitin]].<ref>Hyman, H.L. (1966) "Further Notes on the Occurrence of Chitin in Invertebrates" Biological Bulletin, 130: 1-149. http://www.biolbull.org/cgi/reprint/130/1/94.pdf</ref>
*Setae on the legs of [[krill]] and other small [[crustacean]]s help them to gather [[phytoplankton]].
*Setae on [[gecko]] footpads are small hair-like [[process (anatomy)|process]]es responsible for the animal's ability to cling to vertical surfaces.
==Plant setae==
In [[botany]], "seta" refers to the stalk supporting the [[sporangium|capsule]] of a [[moss]], [[hornwort]] or [[liverwort]], and supplying it with nutrients. The seta has a short foot embedded in the [[gametophyte]] from which it grows. Setae are not present in all mosses, but in some [[species]] they may reach 15 to 20 centimeters in height.<ref>{{aut|[[Peter H. Raven|Raven, Peter H.]]; Evert, R.F. & Eichhorn, S.E.}} (2005): ''[[Biology of Plants]]'' (7th ed.). W.H. Freeman and Company.</ref>
==Artificial setae==
The development of adhesives that detach at will yet display substantial stickiness is of great importance for various technological fields.
<ref>[http://www.physorg.com/news120845139.htmlEngineers create new adhesive that mimicks gecko toe hairs] </ref>
<ref>[http://www.physorg.com/search/search.php?search=+Gecko%2Bsetae Setae Research]</ref>
==See also==
*[[Chaeta]]
*[[Synthetic setae]]
*[[Van der Waals force#Use by animals|Van der Waals force]]
==References==
{{Reflist}}
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{{biology-stub}}
[[Category:Plant anatomy]]
[[Category:Animal anatomy]]
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