In anatomy, a nail is a horn-like structure at the end of an animal's finger or toe. Anatomy (from the Greek anatomia, from ana separate apart from and temnein, to cut up cut open is a branch of Biology that is the consideration A horn is a pointed projection of the Skin on the head of various Mammals consisting of a covering of horn ( Keratin and other Proteins A finger is a type of digit, an organ of manipulation and sensation found in the Hands of Humans and other Primates Normally humans have five digits Toes are the digits of the Foot of an animal Many animal species such as Cats walk on their toes and are described as being Digitigrade See also claw. A claw is a curved pointed appendage found at the end of a toe or finger in most Mammals, Birds, and some Reptiles.

Contents 1 Parts of the nail 2 Health and care 3 Biting 4 Fashion 5 Medical test 6 References 7 See also

Parts of the nail

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. Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Keratins are a family of fibrous structural proteins; tough and insoluble they form the hard but nonmineralized structures found in Reptiles Birds 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. In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species
• eponychium or cuticle, is the fold of skin at the proximal end of the nail. The eponychium or cuticle in Human anatomy refers to the thickened layer of Skin surrounding fingernails and toenails.
• paronychium is the fold of skin on the sides of the nail. Paronychium or the "lateral nail fold" is the term for the soft tissue surrounding the border of the Fingernail or Toenail.
• hyponychium is the attachment between the skin of the finger or toe and the distal end of the nail. In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species
• nail plate is the hard and translucent portion, composed of keratin. Keratins are a family of fibrous structural proteins; tough and insoluble they form the hard but nonmineralized structures found in Reptiles Birds
• nail bed is the adherent connective tissue that underlies the nail, often colloquially referred to as the "quick. "
• 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. The lunula, or lunulae (pl (nail moon is the crescent-shaped whitish area of the bed of a Fingernail or Toenail.

In common usage the word nail usually refers to the nail plate only.

Nails grow at an average rate of 3 millimetres a month. ^[1] 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. ^[2]

This growth record can show the history of recent health and physiological imbalances, and has been used as a diagnostic tool since ancient times. ^[3] Major illness will cause a deep transverse groove to form across the nails. Beau's lines are deep grooved lines that run from side to side on the fingernail. Discoloration, thinning, thickening, brittleness, splitting, grooves, Mees' lines, 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. Mees' lines or Aldrich-Mees' lines are lines of discoloration across the nails of the Fingers and Toes Causes They appear after Leukonychia (or Leuconychia) is a medical term for white discoloration appearing on nails. In Medicine, clubbing, finger clubbing, or digital clubbing is a deformity of the Fingers and fingernails that is associated with a Nails can also become thickened (onychogryphosis), loosened (onycholysis), infected with fungus (onychomycosis) or degenerative (onychodystrophy); for further information see nail diseases. Nail diseases are distinct from diseases of the Skin. Although nails are a Skin appendage, they have their own signs and symptoms which may relate to other Nail diseases are distinct from diseases of the Skin. Although nails are a Skin appendage, they have their own signs and symptoms which may relate to other Onychomycosis means fungal infection of the nail. It is the most common disease of the nails and constitutes about a half of all nail abnormalities Nail diseases are distinct from diseases of the Skin. Although nails are a Skin appendage, they have their own signs and symptoms which may relate to other

Health and care

Nails can dry out, just like skin. The skin is the outer covering of living tissue of an animal (or plant They can also peel, break and be infected. Toe infections, for instance, can be caused or exacerbated by dirty socks, specific types of aggressive exercise, tight footwear and walking unprotected in an unclean environment. A sock is a knitted or Woven type of Hosiery garment for enclosing the human foot Footwear consists of Garments worn on the feet, for protection against the environment and Adornment.

Manicures and pedicures are health and cosmetic procedures to groom, trim, and paint the nails and manage callouses. A manicure is a cosmetic beauty treatment for the Fingernails and Hands performed either at home or by a nail technician A pedicure is a way to improve the appearance of the feet, and their nails It provides a similar service as a Manicure. They require various tools such as cuticle scissors, nail scissors, nail clippers, and nail files. A nail clipper (also called a nail trimmer or nailcutter) is a mechanical device used to trim Fingernails and Toenails. A nail file is a tool used to gently grind down and shape the edges of nails.

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. ^[1] 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 article: Nail biting

Biting the nails often indicates internal tension, stress, boredom, hunger, or it may simply be a habit. Onychophagia or nail biting is a common oral Compulsive habit in children and young adults affecting around 30% of children between 7 to 10 years and 45% of teenagers Boredom is an Emotional state experienced during periods of lack of activities or when individuals are uninterested in the activities surrounding them Hunger is a feeling experienced usually followed by a desire to Eat. Habits are habituated routines of behavior that are repeated regularly tend to occur Subconsciously and tend to occur without directly thinking consciously

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. Tooth enamel is the hardest and most highly mineralized substance of the body and with Dentin, Cementum, and dental pulp is one of the four major

Fashion

Main article: Manicure

Someone whose occupation is to cut any type of nail, apply artificial nails and care for nails is sometimes called a nail technician. A manicure is a cosmetic beauty treatment for the Fingernails and Hands performed either at home or by 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. Nail polish or nail varnish is a Lacquer that is applied to the nails of both the Fingers and Toes usually cosmetically but also as 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 dehydrated or in shock. Dehydration ( hypohydration) is the removal of Water ( hydro in ancient Greek) from an object ^[4] However, this test is not considered reliable in adults. ^[5] This is known as the CRT or blanch test. Capillary refill is the rate at which Blood refills empty Capillaries.

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 ^[6][7]

References

See also

• Leukonychia
• Nail disease
• Hangnail
• Lunula

Leukonychia (or Leuconychia) is a medical term for white discoloration appearing on nails. Nail diseases are distinct from diseases of the Skin. Although nails are a Skin appendage, they have their own signs and symptoms which may relate to other A hangnail or agnail is a small torn piece of Skin near a Fingernail or Toenail. The lunula, or lunulae (pl (nail moon is the crescent-shaped whitish area of the bed of a Fingernail or Toenail.

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