Have You Heard This? It's the Dermis!
The next layer down is the dermis (say: dur-miss). You can't see your dermis because it's hidden under your epidermis. But don't be fooled: it may be below the surface, but the dermis is really important. It contains nerve endings, blood vessels, oil glands, and sweat glands, and all of these play a big part in keeping you and your skin healthy.

The nerve endings in your dermis tell you how things feel when you touch them. They work with your brain and nervous system to let your hand feel the rough skin of an iguana and your feet feel the smushy sensation of sand. Nerve endings on your lips let you feel soft cotton candy and ones in your leg let you feel the itch of a mosquito bite.

The nerve endings of the dermis also work with your muscles to keep you from getting hurt. If you touch something hot, the nerve endings in your dermis respond right away: "Ouch! That's hot!" The nerves quickly send this message to the brain or spinal cord, which then immediately commands the muscles to take your hand away. This all happens in a split second, without you ever thinking about it - all thanks to your dermis!

Your dermis is also full of tiny blood vessels. These keep your skin cells healthy by bringing them the oxygen and nutrients they need. Blood vessels also carry away wastes. It's pretty hard to have a look at your own blood vessels, but older people (like your grandparents' age) have visible blood vessels. That's because as the dermis gets older, it gets thinner, and the skin becomes more transparent.

Oil Meet You There, Sweat!
The dermis is home to the oil glands, too. These are also called sebaceous (say: seh-bay-shuss) glands, and they are always producing sebum (say: see-bum). Sebum is your skin's own natural oil. It rises to the surface of your epidermis to keep your skin lubricated and protected. It also makes your skin waterproof - as long as sebum's on the scene, your skin won't absorb water and get soggy.

Sebum doesn't always work alone, either: it likes to get together with its good friend, sweat. When you sweat, the sweat rises up from your sweat glands onto your epidermis. Even though you can't feel it, you actually sweat a tiny bit all the time. The sweat comes up through pores (say: poors), tiny holes in the skin that allow it to escape. When the sebum meets the sweat, they form a protective film that's a bit sticky.

An easy way to see this film in action is to pick up a pin with your fingers. Then wash your hands well with soap and water, and dry them off completely. Now try to pick up that pin again. It won't be so easy because your sticky layer is gone! (Don't worry - it will be back soon, as your sebaceous and sweat glands create more sticky stuff.) And the next time you take a bath or stay in the pool for a long time, notice how soggy your skin gets. That's because you've washed away your protective layer and the water can get through.

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Jump to another section of this article The Whole Story on Skin Have You Heard This? It's the Dermis! and Oil Meet You There, Sweat! Swell Subcutaneous Fat, Working Together, Whatever the Weather!, and The Skin Wins! Reviewer name and date on last page