Your body functions like a machine, and the most important moving parts of that machine are your organs. There are five vital organs in your body, and they are essential for survival. Those organs are your brain, heart, kidneys, liver and lungs. However, there are 78 total organs in the human body that help it function like a well-oiled machine. These include your skin, spleen, gallbladder, pancreas and more. Each of your 78 organs has a different function to help keep you walking, talking and updating your Facebook status. While there are some organs that don't necessarily do much for people these days (thanks, evolution), others are pretty much the only reason that you're alive. Do you think you know the difference between each of these organs and what they do for you?
We've put together 40 questions about the human body's organs, how they function, and their purpose for being inside of you. If you think you know a thing or two about the human body, you probably know the basics of the body's organs. However, even the best of the best can only get 30 of these questions correct. Do you think you can beat them? Take this tough organ quiz to find out.