You know that the toe bone's connected to the foot bone. And the foot bone's connected to the -- which? Right, the heel bone. And so on..
Here's something about your body you may not know: ever wonder why you can't sneeze with your eyes open? (Admit it; we've all tried.) Well, it turns out you can, it's just that your body automatically blinks for you -- blinking keeps the germs from your sneeze from infecting your eyes. (And no, your eyeballs won't pop out if your eyelids are open.)
Here's another you may not know, as well: that your human body isn't just made up of human cells. What else are you made of? Good question. Bacteria? Stardust? Alien cells? When a Dutch merchant named Antony van Leeuwenhoek looked through a homemade microscope and saw, for the first time, the microorganisms that share the world with us, he changed what humans had believed for centuries. Before van Leeuwenhoek's discovery, what you saw in the world around you was what you believed the world was -- and that didn't include microscopic single-celled organisms, such as the bacteria that causes the common cold or the virus responsible for influenza, or the millions of bacteria that make us who we are.
Biology is, to put it most basically, the study of life and its basic principles help us understand our human physiology -- and the molecular basis for human life as well as human disease. That's everything that makes up you -- and that includes your vital organs, which are essential (vital) for your survival as well as your your biological systems, which carry out all the functions that need to be done to keep you alive. It's called homeostasis, the complex balance and regulation of all the systems of the body, and it's needed for your human machine to run properly. But how much do you know about those organs and systems? Let's find out how much you know about how your body works.