The epidermis is the outer layer of skin. There are no blood vessels, nerve endings, or glands in this skin layer. Though it may not seem like it, this layer of skin is very active. It is constantly being renewed. How does this happen?
The cells at the bottom of this layer are always being produced.
The new cells slowly move up to the surface.
By the time the cells reach the surface, they have died. It's true, the outermost layer of your skin is dead. Don't worry, this is what forms the protective layer. This outer layer is even waterproof.
Dead cells are gradually falling off. As they are shed, they are replaced by other dead cells.
The epidermis also contains cells that give skin its color. These cells are what produces the brown pigment in skin. Everyone's skin has about the same number of these cells. However, these cells of people with darker skin produce more pigment. The amount of pigment depends on two things. Some of it depends on what you inherit from your parents. It also depends on how much sunlight strikes your skin. The more light that hits your skin, the more tanned you get.

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