I was never taught that but I did hear it float around. I think people like to make shit up to make themselves appear to be smart.

Blood is *never* blue. Blood is described as dark red (venous) or bright red (arterial). Our veins look blue because we are looking at them *through* our skin. The blood inside them is dark red and it doesn't reflect light very well.

When i was younger I thought black people had blue blood because of the flash gordon movie. But someone told me it was because without oxygen blood is blue

i thought only royalty had blue blood when i was a kid, but was never told what you were

Yes Sara.....Hemoglobin is the principal determinant of the color of blood in vertebrates. Each molecule has four heme groups, and their interaction with various molecules alters the exact color. In vertebrates and other hemoglobin-using creatures, arterial blood and capillary blood are bright red as oxygen imparts a strong red color to the heme group. Deoxygenated blood is a darker shade of red; this is present in veins, and can be seen during blood donation and when venous blood samples are taken.

Human blood is never blue. Oxygenated blood runs in arteries, and it has a bright red color. Deoxygenated blood runs in veins, and it has a darker red color. In general arteries lie deeper in tissues than veins, and we see veins much more commonly than we see arteries. Markedly deoxygenated blood (for instance the blood returning from the lower extremity to the heart in a person who is running) can appear very dark red in color The blood in veins appears blue due to something called the Tyndall effect. When light is refracted by pigmeneted structures within our skin, it often appears blue in color.

You can put that up there with all the other ignorant unscientific BS we are told throughout our lives, especially as children.

Well, I know that there's that oxygenated blood and unoxygenated blood, and that the difference in the veins is marked as either being red or blue respectively, but I was never told anything about blood being blue....ever.

I was taught that too. And I was pissed off when I discovered it wasn't true...like last year!

I had forgotten that till I read this question!Now I remember!I took a nursing course so I didnt believe it but I remember hearing people talking about it.

Not blue, exactly, but it is more purplish.

Earlier in human history there seems to be a confusion between purple and blue. EXAMPLE in early Hebrew Texts (later the some are now part of the OT Bible) there are references to blue and purple which scholars think are backwards or just plain wrong. This is not the only culture that made this 'mistake' it may very well be part of human development or evolution of the eye and that earlier peoples had a deficiency of cones in the eye. Did you know that some women see more colors than the average person? A tetrachromat is a woman who can see four distinct ranges of color, instead of the three that most of us live with. Red, green, Blue and for a Terachromate an orange color. http://www.post-gazette.com/pg/06256/721190-114.stm for more and http://en.wikipedia.org/wiki/Tetrachromacy What is astounding about this 'find' is that it must be relatively new in our species since it is so rare - had it been around for a long while it would have spread through our species by the general act of multiplication. Color blindness is not a rare thing, http://en.wikipedia.org/wiki/Color_blindness In cases of protanopia and deuteranopia purple looks blue. Scroll down and look at the rainbows on that last link thhe bottom row of color is purple. We humans are one of the few species who see in a range of color so vast, most species are partially color blind - no seeing in black and white, but seeing only a limited range of color like the example of deuteranopia. We do not know when humans first achieved a full range of color that humans have on average today. It has been suggested that the full range of color is a 'recent' addition to human abilities, maybe even so recent that it affected earlier writings that dealt with color. Oxygenated blood is red, Deoxygenated blood is dark red to purplish. It is possible to see 'purple' blood bleeding out of a person if a major vein is hit. If a color blind person who can not see purple sees it it would look bluish.

I heard that two when i was a kid it was quit a when i learnt the truth at school lol.

No Sara ... You being a diva....people just assume that you're blue blooded XP XP j/k !!!

that is what happens isnt it? how else does it happen? im being deadly serious.

No I was not taught that. It could have happened to you because our vains look blue when seen under the skin, that could have led to confusion. Cheers.

I had forgotten that my Gram taught me that.

I just found out!!!! Shit...next your gonna tell me people dont catch colds from being in the cold.

It has to do with the blood in the Capillaries. Since they are near the skin surface the Capillaries can have a blue hue. Hence, the belief that the blood was blue until exposed to air.