Nail (anatomy)
There are other meanings of the word nail
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, it is the hard and transluscent portion, composed of dead 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 completely regrow. 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
A manicure or pedicure is a health and cosmetic procedure to groom and trim the nails. It is accomplished with cuticle scissors, nail scissors, nail clippers, and nail files.