THE BODY

You might think they're unnecessary, because so many people have had their tonsils removed—but tonsils actually serve an important role in your immune system.

Though you might not often think about them, lymph nodes are crucial for your immune system.

At its largest point, the sciatic nerve is about as big around as a man's thumb—plenty big enough to be an important part of the nervous system.

Your stomach may very well be a key player in keeping your mood balanced.

3. Once a year, have a professional look at it.

Fat is actually an important organ.

We're still learning about one of the most important structures of the brain.

You're probably aware of some vestigial body parts, like wisdom teeth, that the human body doesn't really need. But did you know there are several muscles in that category as well?

8. You might want to rethink an ankle tattoo.

The brain is arguably the one organ that makes you who you are—and the largest part of the brain is the neocortex.

Because your nostrils split their workload.

5. You can live without it.