In this topic you will learn how taking care of your skin will help keep your whole body healthy.

Skin has many jobs. One job is to cover your body. Another job is protection. Your skin keeps harmful germs out. Your skin helps you feel whether something is hot or cold, hard or soft. Some of the skin's jobs are done by the epidermis. The epidermis is the outer layer of skin. It is a shield that keeps out dust, dirt, and germs. Water cannot soak into it. Water inside you can't leak out, either.

Skin cells in the epidermis layer contain melanin. Melanin is a substance that gives skin its color. The more melanin a cell contains, the darker the skin is.

You touch the world around you with your epidermis. Your hair and nails grow out of it. Next to each of your hairs is an oil gland. A gland is a part of the body that makes substances that the body needs. Oil glands make waxy oil that covers the surface of your skin and hair. The oil keeps them soft, smooth, and bendable.

No matter how hard you look at your epidermis you won't be able to see your oil glands or the roots of your hairs. That's because the glands and the roots are deep in pits that reach down into the dermis. The dermis is the layer of skin just below the epidermis.

The dermis is the thickest layer of your skin. It is made up of living cells. The dermis contains nerve cells. Nerve cells are the cells that carry messages to and from all parts of the body. Nerve cells in your skin help your brain to understand what is happening in your environment.

The dermis also has sweat glands. When your body gets hot, these glands make sweat. Beads of sweat come out of your pores. A pore is a tiny opening in the skin.