n.
Structure made of keratin that grows on the back of the end of each finger and toe.
Nails consist of a root, under the skin; a translucent plate, attached to a nail bed beneath; and a free edge. Nail plate (and probably bed) cells are produced at the root and pushed forward as new cells form behind them. They die and turn white as they reach the free edge and lose contact with the richly vascularized nail bed, which supplies them with nutrients. Fingernails grow continuously at about 0.5 mm per week; toenails grow more slowly. They protect the tips of fingers and toes and help the fingers pry, pick up small objects, and scratch.