Question: how do our toe nails and finger nails grow?

Faye Didymus answered on 15 May 2012:

Nail growth is related to lots of things: the length of the terminal phalanges (outermost finger bones), age, sex, season, exercise level, diet, and hereditary factors. The growing part of the nail is the part still under the skin and this is the only living part of a nail. The half-moon shape bit by your nail beds (the “lunula” as scientists call it) has a group of cells in it that manufacture keratin, which is a type of protein. The keratin like protein gathers and merges with the nail plate and pushes the entire nail up and out – and that’s how and why our finger and toe nails grow!