Nails are parts of the human body that exist or grow on the fingertips. Nails grow from soft gel-like cells that die, harden, and then form as they begin to grow from fingertips. The epidermis at the base of the nail serves to protect against dirt. The main function of the nail is to protect the fingertips are soft and full of nerves, and enhance the power of touch. Nails are part of bone instead of protein.
In the skin under the nail there are many capillary vessels that have a strong blood supply causing a reddish color. Like bones and teeth, nails are the hardest part of the body because the water content is very small.
The growth of fingernails in a week averaged 0.5 to 1.5 mm, four times faster than the growth of toe nail. Nail growth is also affected by body heat.