Fingernails are primarily made up of a hardened protein called keratin
. This protein is also found in hair, skin, hooves, claws, and horns in animals
. The formation of a nail begins inside a part of the fingertip called the nail root, where cells that will eventually form the nail plate gradually die, harden, and push out of the skin
. As the older cells are compacted and pushed out of the skin by the formation of new cells, they take the hardened, flattened form of the fingernail
. Fingernails serve several functions, such as:
- Protecting the tips of fingers and toes
- Making it easier to scratch an itch or remove a dog hair from your sweater
- Helping us judge how to hold things, detecting pressure changes, and increasing the sensitivity of our fingertips
The part of the nail that we can see is made up of dead keratin cells, which is why it doesn't hurt to cut your nails
. The nails are attached to the nail bed beneath them, and the nail and nail bed separate at the tip of the finger or toe, where the end of the nail sticks out
. Fingernails grow at a rate of about 3 millimeters per month, and toenails grow a little slower
