The top layer, the epidermis produces layers of cells that will push out and die. These horn like cells contain no blood vessels. There are 30 layers. As the top layers get rubbed or washed off, new ones push up from the epidermis. Our fingernails are also made up primarily of dead cells, a horn-like material called keratin.
Growth takes place in the martix, the hidden part of the nail under the cuticle.
The older cells die and harden as they are pushed out. The matrix also includes the lunula, the whitish half-moon area at the base of the nail. Fingernails grow about 0.1 mm per day or 1-2 inches a year. Fingernails grow faster than toenails. Nails in men grow faster than in women.