Believe it or not, that armor plating at the tips of your fingers is made of the same stuff as your hair and skin, a protein called keratin. It’s also in the hooves and horns of animals.
Keratin forms the cells of your hair and skin, too. It also forms cells that are a key part of many glands and that line internal organs. Nails start growing under your skin. As new cells grow, they push old ones through your skin. The part you can see consists of dead cells. That’s why it doesn’t hurt to cut your nails. Fingernails grow about 3.5 millimeters each month. Those are the averages for healthy adults. Whether you’re getting proper nutrition and how well you take care of your nails can affect the growth rate.
Picture Credit : Google