- Fair-skinned people usually burn rather than tan in the sun because they lack melanin, which is responsible for a tan's coloring. Learn more about sunburns.
- Skin is one of the toughest organs in your body, due to the fact that it must constantly protect you from the outside world. Learn more about skin's properties.
- Capillaries are crucial for your skin -- they provide nutrition and help cool your body. Learn more about how capillaries work.
- The epidermis, your outside layer of skin, does not have a direct blood supply. Instead, it's supported by the dermis, the inside layer of skin. Learn more about the layers of your skin.
- Melanocytes are special cells that produce melanin, the pigment that causes you to tan. Learn more about special skin cells.
- Melanoma, a form of skin cancer, emerges as a result of ultraviolet radiation damage to the melanin-producing melanocyte cells. Learn more about melanoma.
- The dermis protects you against burns, punctures and other damage by using nerve endings to alert you when something is hurting your skin. Learn more about nerve endings.
- Keratin, a protein in your cells, is responsible for keeping things tough. Fingernails, horns and hoofs are all strong because of their keratin content. Learn more about keratin.
- The pigment melanin helps you tan because the melanocyte cells that produce it react to ultraviolet light? The light stimulates production. Learn more about the biology behind tanning.
- Redheaded people produce more of one type of melanin (phaeomelanin, which is yellow and red) than the other (eumelanin, which is brown). Redheads typically have a hard time tanning because the increased phaeomelanin, a red pigment, means their coloring will be red instead of brown. Learn more about the role of genetics in tanning.
- Albinos are missing an enzyme called tyrosinase. As a result, their bodies cannot produce melanin. The missing pigment causes a lack of color in their skin, hair and eyes. Learn more about melanin.
- Sunburns don't just age your skin -- they can actually damage your DNA, which can cause mutations that lead to cancer. Learn more about sun damage.
Here are some helpful links: