Fast Facts About Your Blood

Blood -- you know you need it to live, but have you ever wondered why? Here are some fast facts. Blood's like an orchestra made up of four key sections.

Red blood cells carry oxygen. White blood cells help fight infections. Platelets stop cuts from bleeding too much. And plasma transports nutrients and more throughout your body.

Ever wonder where blood gets its red color from? The answer is hemoglobin, a chemical that helps red blood cells carry oxygen. Did you know that blood makes up about 7% to 8% of your body weight? If you're an average-sized woman, you've got around 9 pints. If you're a guy, about 12.

There are eight types of blood. If yours is O-Negative, there's a special upside. You can donate it and potentially help someone with any other blood type who needs an emergency transfusion.

Last, how come mosquitoes are after your blood? Well, actually, only the female ones are. They use it's protein and iron to make their eggs. And those are five fast facts about your blood.