Who came up with this nonsense? Why would blood be blue...ever? It's not!
2006-11-18 09:44:58 · 13 answers · asked by Jason 2 in Science & Mathematics ➔ Biology
Deoxygenated blood is always drawn as blue in text books.
2006-11-18 09:52:17 · answer #1 · answered by Anonymous · 3⤊ 0⤋
Blood isn't actually blue but has a blue appearance through the skin. Blood in arteries is a bright red, this is oxygenated blood, but the arteries are too deep under the skin to see from the surface. Blood in veins, has a blue appearance, but it is actually a purplish red. Blood in veins lacks oxygen. Veins are closer to the surface of the skin so that's why the vessels you see look blue.
2006-11-18 17:56:27 · answer #2 · answered by t1ffanyann3 1 · 1⤊ 0⤋
Veins appear blue because of the effect of light passing through skin and the vessel wall. That's the source of the misconception. Most blood is drawn into evacuated tubes, so there is no oxygen exposure, but too many people don't know that.
The blood in veins is dark crimson.
2006-11-18 17:49:20 · answer #3 · answered by novangelis 7 · 3⤊ 0⤋
First thing: 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. The blood you see when you get hurt is usually venous blood. Arterial blood comes out in spurts. It is just used in diagrams in text books to explain to students where oxygenated and deoxygenated blood moves through the body.
2006-11-18 20:48:32 · answer #4 · answered by sophi p 2 · 0⤊ 0⤋
Blue blood is an English expression recorded since 1834 for noble birth or descent; it is a translation of the Spanish phrase sangre azul, which described the Spanish royal family and other high nobility who claimed to be 'pure', free of Moorish or Jewish blood
2006-11-18 17:54:19 · answer #5 · answered by nzcrusty 2 · 0⤊ 0⤋
Our veins are blue. That's why. Well okay, their green, but they look blue right? It only turns red when it comes into contact with oxygen. It's true!
2006-11-18 17:58:04 · answer #6 · answered by Anonymous · 0⤊ 0⤋
No, it isn't blue. The misconception that it is blue when it is de-oxygenated comes from both the blue-appearance of surface veins, and the depictions in medical texts and charts.
2006-11-18 17:56:23 · answer #7 · answered by Anonymous · 1⤊ 0⤋
its just a color used to teach people how they can differentiate between blood poor in oxygen, and blood rich in oxygen. and all veins carrying blood poor in oxygen actually do look blue. but blood will always be red.
2006-11-18 18:01:16 · answer #8 · answered by Suzy J 2 · 1⤊ 0⤋
In some animals (e.g. horseshoe crabs), their blood is actually blue. But human blood is not.
I learned about this on a campout in Fire Island from the park ranger.
2006-11-18 17:49:05 · answer #9 · answered by Joshua Z 4 · 1⤊ 0⤋
Mostly b/c when you look at the superficial veins on the skin of a fair-skinned person, they look blue
2006-11-18 17:48:05 · answer #10 · answered by Alex 2 · 1⤊ 0⤋