Today’s Wonder of the Day was inspired by Jaden. Jaden Wonders, “How many skin layers do we have” Thanks for WONDERing with us, Jaden!

Have you ever WONDERed what your body’s largest organ is? Could it be your heart? After all, your heart has to be plenty big and strong to pump all that blood throughout your body.

What about your lungs? They have to be fairly large to hold all the air you need to breathe every day. Or your brain? Without a big brain, human beings wouldn’t be so smart.

While your heart, lungs, and brain are all big organs, they’re not nearly your body’s largest. In fact, you can see your body’s largest organ right now. What are we talking about? Your skin, of course!

While we usually think of bodily organs as those important parts inside our bodies, your skin is actually an organ that covers the entire outside of your body. And it’s big! If you stretched out all the skin covering a 150-pound adult, it would cover over two square yards and weigh around nine pounds!

Do you really need all that skin? You bet you do! Your skin is very important for a variety of reasons. For example, the primary role your skin plays is that of protector. Your skin covers and protects everything inside your body, including your muscles, bones, nerves, blood vessels, and internal organs.

Without your skin, you’d be a mess. It’s not very pleasant to imagine yourself without skin. You’d have muscles and organs moving about, sticking out, and falling all over the place. Yuck! Thanks to your skin, though, all those things stay inside right where they’re supposed to be.

Your skin protects you at the same time it’s holding things in place. The thinnest skin on your body forms your eyelids, yet these tiny bits of skin do an amazing job of protecting your eyes. The thickest skin on your body makes up the soles of your feet. Your foot muscles would probably be really sore if they didn’t have your skin to protect them when you run around barefoot during the summer!

Your skin also helps keep your body at just the right temperature. If you go outside in hot or cold weather, your body temperature may tend to rise or fall above the normal temperature of 98.6º F. When this happens, a part of your brain called the hypothalamus will send messages to your skin to help regulate your body’s temperature.

When you get too hot, your skin helps you cool down. Blood vessels in the skin move more warm blood toward the skin’s surface, so the heat can be released. Glands in the skin produce sweat which cools the body when it evaporates. Likewise, the skin can cause your blood vessels to constrict, moving warm blood away from the skin to keep you warmer when you get too cool.

Finally, your skin allows you to have the sense of touch. Can you imagine life without being able to touch things and feel the warmth of the Sun on your skin? While your eyes allow you to see and your nose allows you to smell, it’s your skin that allows you to feel. The next time you run your fingers through the soft, luxurious fur of your favorite pet, thank your skin for allowing you to feel something so WONDERful!

Standards: NGSS.LS1.A, CCRA.L.3, CCRA.L.6, CCRA.R.1, CCRA.R.2, CCRA.R.4, CCRA.R.10, CCRA.SL.1, CCRA.SL.2

Wonder What's Next?

Tomorrow’s Wonder of the Day is too hot to handle!