The Skin In a Nutshell
Your skin is your body's largest organ
. It protects your inner organs, keeps harmful stuff out of your body, and provides some protection from the sun. Your skin also helps your body turn sunlight into vitamin D
, an important nutrient for a strong, healthy body. It keeps your temperature even and tells your brain when something feels good, bad, hot, or cold. The condition of your skin can tell a health professional a lot about your health. back to top
Did you know that...
Getting Under Your Skin
- The skin is your body's largest organ.
- The life of a skin cell is about a month.
- In a square inch of skin there are about 30 million cells, 100 sebaceous glands, 600 sweat glands, and 65 hairs. back to top
The skin is made up of two main layers, the outer layer that you see (called the epidermis
), and the inner layer (called the dermis
). back to top
The Outer Layer
The outer portion, or epidermis
, covers your entire body. It's a very thin layer of skin that's almost transparent. It's thickest on the bottoms of your feet and the palms of your hands. The epidermis is divided into three main layers: the basal cell layer on the bottom, the squamous cell layer in the middle, and the stratum corneum on the top.
The Inner Layer
- Basal Cell Layer. This is the layer closest to the dermis. It's where new skin cells are made. This layer of the epidermis contains melanin, the material that gives your skin its color. If you have light skin, you don't have much melanin. If you have dark skin, you have lots of melanin. Melanin protects your skin from the harmful rays of the sun. The more melanin you have, the more natural protection you have sunblock.
- Squamous Cell Layer. When new skin cells reach this middle layer, they flatten out and are called squamous cells.
- Stratum Corneum. This layer contains an important material called keratin. Keratin protects your skin from harmful things like pollution and also helps to keep water in your skin. When skin cells reach this layer, they start to die and eventually fall away. Then new skin cells push up and take their place. back to top
The second layer of skin (the dermis
) is right under the epidermis. It contains proteins called collagen
that help the skin stretch and stay strong. This layer also contains lots of nerves, which send messages to your brain when you feel pain or a touch. It's also home to sweat glands
, sebaceous glands
, hair follicle
s, and blood vessels
Right under the dermis is a thick layer of fat. You have the most fat when you're a baby. As you get older, this layer gets thinner and thinner. The fat layer is important because it keeps you warm. It also gives different body parts their shapes (like your cheeks, for example). back to top
The Life of a Skin Cell
New skin cells are "born" in the bottom part of the epidermis. After they are made, they slowly move up toward the top layer of the epidermis. On their way, they push other skin cells up to the surface. When they reach the top layer of the epidermis, they die and fall off to make room for new skin cells. back to top