A while ago we asked for your (anonymous) embarrassing science questions.
First we answered some of the weirdest requests we had (from how birds pee to whether or not fish get thirsty). Now we're moving on to ~bodies~. All questions are pretty much as we received them.
1. "What actually are blackhead pimples?"
2. "Can you sneeze with your eyes open?"
3. "My boyfriend keeps telling me girls had testicles at birth but they rolled up inside them and turned into ovaries... true or not true?"
4. "What's the purpose of wisdom teeth?"
5. "Do you have blue blood in your body?"
All those diagrams that showed arteries as red and veins as blue lied to you. Deoxygenated blood is a darker red than oxygenated blood, but calling it blue would be a bit of a stretch (there's an interesting discussion to be had about how the perception of colour plays into this, but we'll save that for another time). Think about it: If there were blue blood in your veins, it'd come out that way when you cut yourself, right?
Veins look blue, however, when you view them through your skin because of the different wavelengths different colours of light have (blue is shorter than red) and how far into your skin the blood vessels you're looking at are.