You may not think about your nails, unless you just painted them blue or your mom says it's time to trim them. But your nails have a job to do. The hard surface of your nails helps to protect the tips of your fingers and toes. And your fingernails make it easier to scratch an itch or remove a dog hair from your sweater.

Nails themselves are made of keratin (say: ker-uh-tin). This is the same substance your body uses to create hair and the top layer of your skin. You had fingernails and toenails before you were even born. Where do they come from?

It may look like your fingernails and toenails start growing where your U-shaped cuticle (say: kyoo-tih-kul) begins. But there's more going on under the surface. Nails start in the nail root, hidden under the cuticle.

When cells at the root of the nail grow, the new nail cells push out the old nail cells. These old cells flatten and harden, thanks to keratin, a protein made by these cells. The newly formed nail then slides along the nail bed, the flat surface under your nails. The nail bed sits on top of tiny blood vessels that feed it and give your nails their pink color.

Your fingernails grow slowly - in fact, they grow about one tenth of an inch (2.5 millimeters) each month. At that rate it can take about 3 to 6 months to completely replace a nail.

Where your nail meets your skin is your cuticle. Cuticles help to protect the new nail as it grows out from the nail root. The lunula (say: loo-nyuh-luh) - which comes from the Latin word for "moon" - is that crescent half circle of pale skin just above the cuticle. Your lunula is easiest to see on your thumbnails.

Nail Care
You might need an adult to help you trim your fingernails and toenails, which can be a little challenging. A nail clipper or a pair of nail scissors may be used. To smooth jagged edges, you can use a nail file or emery board, which works like sandpaper.

Fingernails should be trimmed straight across and slightly rounded at the top. Having nicely trimmed nails can keep you from biting or picking at them, which can lead to infections. It's also a good idea to moisturize nails and cuticles regularly. A little hand lotion will do the trick.

Because toenails are slowpokes (they don't grow nearly as fast as fingernails), they don't need to be trimmed as often. They should be trimmed straight across, which can be difficult, so you might want to ask a parent for help.