What Are Nails?

Nails are plates of hardened protein packed into layers. Nails support and protect the sensitive tips of our fingers and toes. We use our nails for many tasks, like picking up small objects, scratching an itch, and untying a knot.

What Are the Different Parts of Nails?

Nails have many parts:

• The matrix (MAY-triks) is the area at the base of the nail that makes new cells.
• The lunula (LOON-yuh-luh) is the white part of the matrix that looks like a crescent moon.
• The nail plate is the largest part of the nail. It looks pink from the network of tiny blood vessels in the skin beneath it.
• The nail bed is underneath the nail plate.
• Nail folds are the areas of skin around the nail plate that hold it in place.
• The cuticle (KYOO-tih-kul) is the thin layer of skin that comes from the nail fold near the lunula and attaches to the nail plate.

How Do Nails Grow?

Cells grow in the matrix at the base of the nail. As new cells are made, they move up to the surface of the skin and push the older cells up and forward toward the tip of a finger or toe. The cells get pressed tightly together to make a thin plate. Plates pile into layers to form the nail. During this process the cells become hard and die. This hardening is called keratinization (kair-eh-tih-neh-ZAY-shen).

If an injury causes a nail to tear off, the nail will grow back if the matrix isn't severely injured.