Roses are red and violins are blue, if blood is red then why the vein is blue? We all know that our blood color is red, but have you ever wondered, if our blood is red then why do our veins look blue or purplish?
Blood is a human body fluid that is thicker than water. Its temperature is one degree higher than body temperature around 38°C (100.4°F). How much blood we have in our body is depend on our size and body weight. For estimation, a man who weighs about 70 kg (about 154 pounds) has about 5 to 6 liters of blood in his body. Blood itself has a trinity function to sustain our life.
As transportation, The blood transports oxygen from the lungs to the cells of the body, where it is needed for metabolism. As a regulator, The blood helps to keep certain things in the body in balance. for example, it makes sure that the right body temperature is maintained. As a protector, This involves solid parts of the blood such as blood platelets and various substances that are dissolved in the blood plasma. White blood cells and certain chemical messengers also play an important role in the immune system.
Human blood is red because of hemoglobin. This protein in the red blood cell that carries oxygen contains four atoms of iron, which reflect red light. Blood does change color somewhat as oxygen is absorbed and replenished. It changes from red to dark red. So, yes Blood has 50 shades of red but it doesn’t change from red to blue. Your vein may look blue or green looking but if you slide a needle into it and draw a couple of drops of blood it will look dark red or burgundy-ish. It happens because the blood is deoxygenated, but it doesn’t turn blue.
Then, why does our vein blue looking and in some people green-colored? According to Dr. Kleber Fertrin, an assistant professor of hematology at the University of Washington School of Medicine in Seattle for LiveScience.com “(The blue or green vein) is almost like an illusion caused by the fact that (the vein is) under this small but significant layer of skin,” He continued “The colors we see are based on the wavelength that our retina perceives.” And varying layers of skin make the wavelengths scatter in different ways, he said. Under darker skin, veins often appear green. And they can appear blue or purplish under lighter skin tones. That’s because green and blue wavelengths of light are shorter than red wavelengths. Red light is better at penetrating human tissue than blue light, So while red wavelengths are absorbed by our skin, the green and blue are reflected and scattered back to us, Fertrin said.
Blue blood may exist in a fantasy novel or sci-fi as the most non-human character in Star Wars have colorful blood. Just not in our blood. The color of the blood itself doesn’t change it stays red; it’s just a matter of how our eyes play a trick on Us. But if your blood has copper instead of iron like spider, octopus, crabs, and lobster, then yes your blood will be blue. well, it turns out blue blood does exist in nature after all, only not in humans.
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