Nail (anatomy)
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- This article discusses the anatomical nail. For other uses of the term, see nail.
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Anatomy
In anatomy, a nail is a horn-like piece at the end of a human or animal finger or toe. See also claw and hoof.
Fingernails and toenails are composed of:
- the nail matrix or the root of the nail - this is the growing part of the nail still under the skin at the nail's proximal end.
- eponychium of cuticle which is the fold of skin at the proximal end of the nail.
- paronychium which is the fold of skin on the sides of the nail.
- hyponychium which is the attachment between the skin of the finger or toe and the distal end of the nail.
- nail plate which is what we think of when we say nail, the hard and translucent portion, composed of keratin.
- nail bed which is the adherent connective tissue that underlies the nail.
- lunula which is the crescent shaped whitish area of the nail bed.
Fingernails require 3 to 6 months to regrow completely. Toenails require 12 to 18 months. Any major illness will cause a groove to form in the nails, marking in time the past medical history of its owner. These are called Beau's lines.
Nails can become thickened (onychogryphosis), loosened (onycholysis), infected with fungus (onychomycosis) or degenerative (onychodystrophy); for further information see nail diseases.
Care
A manicure or pedicure is a health and cosmetic procedure to groom, trim, and paint the nails. It is accomplished with cuticle scissors, nail scissors, nail clippers, and nail files, among various other tools. To paint the nails, nail lacquer (also known as nail polish or fingernail polish) is manually applied and allowed to dry. In 2003 the first ink nail printer NailJet Pro was released. It allowed individuals to print custom hi-resolution colour images on their nails.Template:Ref
In some parts of Asia, similar but larger nail-art printers have been set up near bookstores and other popular destinations of young people. They work much like picture-taking booths.
Fashion and culture
In the late 20th century, artificial nails for women became widely popular. The artificial nails are not a replacement, but an extension for natural nails. There are two main approaches to creating artificial nails—tips and forms. Tips are lightweight plates that are glued on the natural nail. Forms are fit over the nail and then an artificial nail is molded and the form is removed. With both approaches several materials can be used to glue the tips of form artificial nails. One popular material is acryl—a mixture of powder and ethymethacrylate that hardens in 30–40 seconds after application. Acryl can be removed in 20 minutes using a variety of solvents. Another material, gel, hardens under ultraviolet light and is more lasting and more expensive. It can only be removed by cutting it off. Other materials can be used, as well as combinations of them. There are also cheaper flexible tips that can be quickly glued at home without help from a professional. Artificial nails are produced in a variety of colours and can use "special effects" such as contours and sparkles.
In some (Asian) cultures men also will grow long fingernails, or only the nail on the little finger, to show that they do not do much manual labor, but instead work in an office setting.
Some guitar players, notably classical guitar players and fingerstyle players, will purposely grow long nails on one hand. Their longer nails aid in their "picking" the guitar strings, so that they act as small, easily-manueverable guitar picks. Care thereof becomes a daily ritual and a mark of pride. The obsessive attention paid to nails can seem effeminate to the uncultured, however it is another mark of the dedication that accompanies the serious musician.
Torture
The whole area of the nail is connected to the finger. Because of that removal of a nail can be painful. Sometimes this has to be done for medical reasons (for example, if the nail becomes infected or mechanically damaged; this is usually done under anesthesia).
Because the procedure is extremely painful, its variations were widely used for torture in the past and are still used occasionally. One variation is pulling the nail off completely with some kind of pliers. It was usually administered together with other methods of torture. Another variation is inserting sharp objects under the nails, including needles and metal nails. If sterile and sufficiently small tools are used, this method will not leave any permanent damage, while still causing excruciating pain.
Myth
It is commonly claimed that nails and hair will continue growing for several days after death. This is a myth; the appearance of growth is actually caused by the retraction of skin as the surrounding tissue dehydrates, making nails and hair more prominent.
Biting
Cultural Effects
Many people bite their nails. It is considered to be a mildly embarrassing habit in some cultures. Biting one's nails can indicate internal tension or stress.
Health Effects
However, biting the nails can result in the transportation of germs that are buried under the surface of the nail into the mouth. In fact, nail salons use tools that potentially affect a human in a similar way. “If their (nail tools such as files) 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. In fact, over 100 bacterial skin infections in 2000 were traced to footbaths in nail salons. Thus, one can see that many pathogens have the ability to "live" inside of a nail, and because of this biting the nails can potentially cause health issues.Template:Ref
References
- Template:Note ImagiNail Website (http://www.imaginail.com)
- Template:NoteTram Kim Nguyen, "The Truth About Germs" (http://www.fitnessmagazine.com/fitness_and_health/070303_germs.jsp), Fitness Magazine. Accessed 10 April 2005.
| Integumentary system |
| Skin - Sweat glands - Hair - Nails |
| Skin |
| Epidermis (Stratum corneum, Stratum lucidum, Stratum granulosum, Stratum spinosum, Stratum germinativum/basale) |
| Dermis - Subcutis |
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