The above image shows a close-up of the inside of a "fleshy" tunnel. Could it be an intestine? It could. Or it could be something else. But what is an intestine? It is an organ in the digestive system. The digestive system does what you think it does - it digests your food.
But does the inside of your intestine really look like a tunnel? Some would say an intestine looks more like a mountain range, with peaks and valleys. Why? The peaks and valleys would represent the villi that are inside of the intestines. They increase the surface area of the intestine so they can absorb as many nutrients as possible.
So what is another function of the digestive system? Absorption. What happens when you get sick? Does the digestive system work properly? What nutrients and vitamins do you need in order to make sure that your digestive system and your whole body works properly? What do the villi in the intestines have to do with these processes? As you read, think about the organs that help you digest and absorb the nutrients in your foods. Also, consider how healthy eating leads to healthy organ systems.
Image copyright Christian Darki, 2014. www.shutterstock.com. Used under license from Shutterstock.com.