WHAT'S INSIDE: HUMAN BODY
- Body Parts
- Body Systems
Vestigial organs are like the contents of your junk drawer: an assortment of objects that once had a purpose or might come in handy. What can these evolutionary mementos tell us?
But no matter how many times you've doodled one on a piece of paper or touched your chest when expressing affection for someone, there's probably a lot you don't know about it. So what are five things you don't know about your heart?