Blood is one of the most important parts of our bodies, transporting vital oxygen, vitamins and minerals around the various organs. The fact it is so significant, along with the fact that it has a striking appearance due to its strong red color, means that it is also rather dramatic. In fact, blood is often used in movies and television shows to signify injury or harm. Despite the important role it plays though, there are plenty of things that people don’t know about it.
Despite the common belief that blood is blue when it isn’t oxygenated, blood is never that color. The red liquid simply looks blue under the skin because of the way that blood interacts with light in veins.
Although humans only have red blood, other animals on the planet have a wide range of different colored blood. This includes some crustaceans having blue blood while a particular species of leech bleeds a green liquid.