What Are Fingernails?
A fingernail is produced by living skin cells in the finger. A
fingernail consists of several parts including the nail plate (the
visible part of the nail), the nail bed (the skin beneath the nail
plate), the cuticle (the tissue that overlaps the plate and rims the
base of the nail), the nail folds (the skin folds that frame and
support the nail on three sides), the lunula (the whitish half-moon
at the base of the nail) and the matrix (the hidden part of the nail
unit under the cuticle).
Fingernails grow from the matrix. The nails are composed largely of
keratin, a hardened protein (that is also in skin and hair). As new
cells grow in the matrix, the older cells are pushed out, compacted
and take on the familiar flattened, hardened form of the fingernail.
The average growth rate for nails is 0.1 mm each day (or 1 centimeter
in 100 days). The exact rate of nail growth depends on numerous
factors including the age and sex of the individual and the time of
year. Fingernails generally grow faster in young people, in males,
and in the summer.
Fingernails grow faster than toenails. The fingernails on the right
hand of a righthanded person grow faster than those on their left
hand, and vice versa.
Last Editorial Review: 7/6/2004