Nail (anatomy) 397986 225987198 2008-07-16T09:53:13Z Tresiden 4049320 Reverted edits by [[Special:Contributions/24.16.104.86|24.16.104.86]] to last version by WadeSimMiser (using [[WP:HG|Huggle]]) {{otheruses3|Nail}} {{redirect|Fingernails|the album|Fingernails (album)}} {{Refimprove|date=July 2007}} [[Image:Fingernail label.jpg|thumb|right|200px|Anatomy.]] In [[anatomy]], a '''nail''' is a [[horn (anatomy)|horn]]-like structure at the end of an animal's [[finger]] or [[toe]]. See also [[claw]]. ==Parts of the nail== [[Image:Fingernails1.JPG|thumb|Fingernails.]] [[Image:Toes.jpg|thumb|Toenails.]] Anatomically '''fingernails''' and '''toenails''' are made of a tough [[protein]] called [[keratin]] and have many different parts: * The free edge is the part of the nail that extends past the finger, beyond the nail plate. There are no nerve endings in the nail - this is the growing part of the nail still under the skin at the nail's [[proximal]] end. The average thickness of this portion of the nail is .017 inches. * [[eponychium]] or cuticle, is the fold of skin at the proximal end of the nail. * [[paronychium]] is the fold of skin on the sides of the nail. * [[hyponychium]] is the attachment between the skin of the finger or toe and the [[Anatomical terms of location|distal]] end of the nail. * [[nail plate (anatomy)|nail plate]] is the hard and translucent portion, composed of [[keratin]]. * nail bed is the adherent connective tissue that underlies the nail, often colloquially referred to as the "quick." * [[lunula (anatomy)|lunula]] is the crescent shaped whitish area of the nail bed (when visible) * [[nail fold]] a fold of hard skin overlapping the base and sides of a fingernail or toenail. In common usage the word ''nail'' usually refers to the nail plate only. <!-- [[Image:2007-04-10 029.JPG|thumb|right|Nail with split side]] This image does not really illustrate your caption at this image size. Please consider photo editing to enhance the view. In addition, you should add text to correlate with the image.--> [[Image:BothHand.jpg|thumb|left|Long, manicured nails are a fashion statement.]] Nails grow at an average rate of 3 millimetres a month. <ref>[http://www.medterms.com/script/main/art.asp?articlekey=7740 Toenail Definition - Medicine.net]</ref> Fingernails require 3 to 6 months to regrow completely. Toenails require 12 to 18 months. Actual growth rate is dependent upon age, gender, season, exercise level, and hereditary factors. Contrary to popular belief, nails do not continue to grow after death; the skin dehydrates and tightens, making the nails (and hair) appear to grow.<ref name="growth">[http://www.usd.edu/esci/age/content/natural_clocks/fingernails.html Nail growth] usd.edu</ref> This growth record can show the history of recent health and physiological imbalances, and has been used as a diagnostic tool since ancient times.<ref>[http://www.aad.org/public/Publications/pamphlets/NailHealth.htm American Academy of Dermatology - Nail Health]</ref><!--{{ref|diagnoses}}--> Major illness will cause a [[Beau's lines|deep transverse groove]] to form across the nails. Discoloration, thinning, thickening, brittleness, splitting, grooves, [[Mees' lines]], [[leukonychia|small white spots]], receded lunula, [[clubbing]] (convex), flatness, spooning (concave) can indicate illness in other areas of the body, nutrient deficiencies, drug reaction or [[poisoning]], or merely local injury. Nails can also become thickened ([[Nail diseases#onychogryposis|onychogryphosis]]), loosened ([[Nail diseases#onycholysis|onycholysis]]), infected with fungus ([[onychomycosis]]) or degenerate ([[onychodystrophy]]); for further information see [[nail disease]]s. ==Health and care== [[Image:ToeNailInjury.jpg|thumb|Mechanical injury can result in the nail being dropped.]] Nails can dry out, just like [[skin]]. They can also peel, break and be infected. Toe infections, for instance, can be caused or exacerbated by dirty [[sock]]s, specific types of aggressive exercise, tight [[footwear]] and walking unprotected in an unclean environment.{{Fact|date=July 2007}} [[Manicure]]s and [[pedicure]]s are health and cosmetic procedures to groom, trim, and paint the nails and manage callouses. They require various tools such as cuticle scissors, nail scissors, [[nail clipper]]s, and [[nail file]]s. Nail tools used by different people may transmit infections. Regarding nail tools such as files, "If they're used on different people, these tools may spread nail fungi, staph bacteria or viruses", warns Rick Lopes, a spokesperson for the California Board of Barbering and Cosmetology.{{ref|germs}} In fact, over 100 bacterial skin infections in 2000 were traced to footbaths in nail salons. To avoid this, new improved contactless tools can be used, for example, gel and cream cuticle removers instead of cuticle scissors. ==Biting== {{main|Nail biting}} Biting the nails often indicates internal tension, [[stress (medicine)|stress]], [[boredom]], [[hunger]], or it may simply be a [[habit (psychology)|habit]]. Nail biting can result in the transportation of germs that are buried under the surface of the nail into the mouth. It may also cause excessive or abnormal wear of [[tooth enamel]].{{Fact|date=September 2007}} ==Fashion== {{main|Manicure}} Someone whose occupation is to cut any type of nail, apply artificial nails and care for nails is sometimes called a nail technician. The place where a nail technician works may be called a nail salon or nail shop (also "nailshop"). Painting the nails with [[nail polish]] (also known as nail lacquer) is a common practice dating back to at least 3000 B.C. Ornamented fake nails are sometimes used to display designs, such as stars or sparkles, on nails. They are also used to make nails look longer. == Medical test == Health care and pre-hospital care providers (EMTs or paramedics) often use the fingernail beds as a cursory indicator of distal tissue perfusion of individuals who may be [[Dehydration|dehydrated]] or in [[Shock (medical)|shock]].<ref>[http://www.co.monterey.ca.us/health/EMS/pdfs/EMSManual.pdf Monterey County EMS Manual]. Chapter XI, ''Patient assessment''.</ref> However, this test is not considered reliable in adults.<ref>[http://www.ncbi.nlm.nih.gov/pubmed/2039096?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA NIH Website]. Limitations of capillary refill test.</ref> This is known as the [[Capillary refill|CRT or blanch test]]. Procedure: briefly depress the fingernail bed gently with a finger. This will briefly turn the nailbed white; the normal pink colour should be restored within a second or two. Delayed return to pink colour can be an indicator of certain shock states such as [[hypovolemia]] <ref>[http://www.nlm.nih.gov/medlineplus/ency/article/003394.htm NIH Website]. Capillary nail refill test.</ref><ref>[http://www.stlukes-stl.com/health_content/health_ency/1/003394.htm St. Luke's Hospital]. Capillary nail refill test.</ref> ==References== {{Reflist}} <div class="references-small"> <!--# {{note|growthrate}} [http://www.medterms.com/script/main/art.asp?articlekey=7740 Toenail Definition - Medicine.net] --> <!--# {{note|diagnoses}} [http://www.aad.org/public/Publications/pamphlets/NailHealth.htm American Academy of Dermatology - Nail Health]--> * {{cite journal | author = Barker D | title = Nail biology and nail science | journal = Int J Cosmet Sci | volume = 29 | issue = 4 | pages = 241–75 | year = 2007 | doi = 10.1111/j.1467-2494.2007.00372.x}} * {{cite journal | author = Haneke E | title = Surgical anatomy of the nail apparatus | journal = Dermatol Clin | volume = 24 | issue = 3 | pages = 291–6 | year = 2006 | pmid = 16798426 | doi = 10.1016/j.det.2006.03.007}} <!--# {{note|diagnoses}} [http://lngnails.co.uk LNG Nails Magazine - Nail Health]--> </div> ==See also== {{commonscat|Nails}} * [[Leukonychia]] * [[Nail disease]] * [[Hangnail]] * [[Lunula_%28anatomy%29|Lunula]] {{integumentary_system}} [[Category:Integumentary system]] [[Category:Nails| ]] [[Category:Nail diseases]] [[ar:ظفر (تشريح)]] [[gn:Pysãpe]] [[ay:Sillu]] [[ca:Ungla]] [[cs:Nehet]] [[de:Nagel (Anatomie)]] [[et:Küüs]] [[es:Uña]] [[eo:Ungo]] [[fa:ناخن]] [[fr:Ongle]] [[ko:발톱]] [[io:Unglo]] [[id:Kuku]] [[it:Unghia]] [[he:ציפורן]] [[jv:Kuku]] [[la:Unguis]] [[lt:Nagai]] [[hu:Köröm]] [[nl:Nagel (anatomie)]] [[ja:爪]] [[no:Negl]] [[nn:Nagl]] [[oc:Ongla]] [[pag:Kuko]] [[pl:Paznokieć]] [[pt:Unha]] [[qu:Sillu]] [[ru:Ногти]] [[simple:Fingernail]] [[sk:Necht]] [[sl:Noht]] [[fi:Kynsi]] [[sv:Naglar]] [[tl:Kuko]] [[tg:Нохун]] [[tr:Tırnak]] [[fiu-vro:Küüds]] [[yi:נאגל (אנאטאמיע)]] [[yo:Èkánná]] [[diq:Nenıg]] [[zh:指甲]]