Are Humans Really Bluebloods?

Have you ever heard the claim that human blood is blue before it hits the air? This is a common misconception that seems to have taken on a life of its own, but the truth is that human blood is never blue.

So, where did this idea come from? The reason that veins appear blue is due to the way that light penetrates and reflects off of the skin. When light penetrates the skin, it is absorbed by the blood in the veins. However, because blue light has a shorter wavelength and is absorbed less easily than other colors, it is reflected back to the surface of the skin. This is what gives veins the blue color that we see.

But while veins may appear blue, the blood inside of them is actually always red. The color of blood is determined by the presence of a protein called hemoglobin, which carries oxygen to the body’s cells. Hemoglobin is red when it is carrying oxygen, and it remains red even when it is not carrying oxygen.

So, where did the idea that blood is blue before it hits the air come from? It’s hard to say for sure, but it may be a misunderstanding of the way that light reflects off of the skin. Some people may have assumed that the blue color of veins means that the blood inside is also blue, but this is not the case.

In conclusion, human blood is never blue. It is always red, regardless of whether it is oxygenated or deoxygenated. The blue color of veins is an optical illusion caused by the way that light reflects off of the skin. So the next time someone tells you that blood is blue before it hits the air, you can confidently set the record straight!