ANOTHER AMAZING PART OF YOUR BODY IS THE SKIN THAT COVERS YOU

You might be surprised to find out that your skin is the biggest organ in your body. No matter how you think of it, your skin is very important. It covers and protects everything inside your body. Without skin, people's muscles, bones, and organs would be hanging out all over the place. Skin holds everything together. Look down at your hands for a minute. Even though you can't see anything happening, your epidermis is hard at work. At the bottom of the epidermis, new skin cells are forming. When the cells are ready, they start moving toward the top of your epidermis. This trip takes about 2 weeks to a month. As newer cells continue to move up, older cells near the top die and rise to the surface of your skin.

What you see on your hands (and everywhere else on your body) are really dead skin cells. Though you can't see it happening, every minute of the day we lose about 30,000 to 40,000 dead skin cells off the surface of our skin. That's almost 9 pounds (4 kilograms) of cells every year! Melanin gives skin its color. The darker your skin is, the more melanin you have. The next layer down is the dermis. The dermis contains nerve endings, blood vessels, oil glands, and sweat glands. The nerve endings in your dermis tell you how things feel when you touch them. They work with your brain and nervous system, so that your brain gets the message about what you're touching. Your dermis is also full of tiny blood vessels. These keep your skin cells healthy by bringing them the oxygen and nutrients they need and by taking away waste. The dermis is home to the oil glands, too and you also have sweat glands on your epidermis.

The third and bottom layer of the skin is called the subcutaneous layer. It is made mostly of fat and helps your body stay warm and absorb shocks; like if you bang into something or fall down. The subcutaneous layer also helps hold your skin to all the tissues underneath it. This layer is where you'll find the start of hair as well. Each hair on your body grows out of a tiny tube in the skin called a follicle. You have hair follicles all over your body, except on your lips, the palms of your hands, and the soles of your feet. There are more than 100,000 follicles on your head alone! Your blood vessels, hair, and sweat glands cooperate to keep your body at just the right temperature. The body is pretty smart; it knows how to keep your temperature right around 98.6 degrees Fahrenheit to keep you and your cells healthy. To cool you down, sweat glands also swing into action by making lots of sweat to release body heat into the air. When you're cold, your blood vessels keep the body from losing heat by narrowing as much as possible and keeping the warm blood away from the skin's surface. You might notice tiny bumps on your skin. Most kids call these goose-bumps. So there you have it--a tour of your incredible covering called skin.