The blood in our bodies is red, but it is true that some animals have blue blood: for example spiders and molluscs. This is because their blood contains a blue pigment called hemocyanin that acts like a stain. But human blood is just red since it contains hemoglobin, which is a red-coloured protein containing iron.
Hereโs a good article if you want to find out more: http://chemistry.about.com/od/biochemistry/a/Is-Deoxygenated-Human-Blood-Blue.htm ๐
Thsnks for your explication, it was really easy to understand. But I also heard that the blood is originaly blue and become red with the conact of the air!?
Yui
Hi Yui,
Glad to be able to help! The idea that blood is blue in humans is actually a myth. Blood that contains hemoglobin (such as in humans and other vertebrates) is always red. The reason veins appear to be blue is due to the lack of oxygen. If you want to test this, try holding your hand up to a light source: it will glow red because of the red blood ๐
Comments
Yui commented on :
Thsnks for your explication, it was really easy to understand. But I also heard that the blood is originaly blue and become red with the conact of the air!?
Yui
Anthea commented on :
Hi Yui,
Glad to be able to help! The idea that blood is blue in humans is actually a myth. Blood that contains hemoglobin (such as in humans and other vertebrates) is always red. The reason veins appear to be blue is due to the lack of oxygen. If you want to test this, try holding your hand up to a light source: it will glow red because of the red blood ๐