Is blood blue or red?

[GameOverRob]

oopps meant to say veins lol was doing other things whilst typing

[OxideNOS]

Have anybody seen Blue blood coming out from a human body?............NO. Its' RED.

[+dave164 Subscriber¹]

Its red... i think blue is from a fly or something like that..

When the O2 reacts with the haemoglobin in the RED blood cells its creates oxyhaemoglobin which is red i think. Plasma carries the rest of the properties such as CO2, urea, etc..

[Spyker]

it is blue when deoxgynated and red when oxgynanted Oxyheamoglobin is red, and this is formed when oxgyen and heamoglobin are present together, affer the oxgyen has diffuised it will turn blue. this interaly depends on where in the body you are refering too.

^beat me to it, and carbon diioxde also bonds to heamoglobin,

[+dave164 Subscriber¹]

I swear it doesn't Spyker, i thought CO2 was carried by plasma..

Ive never heard of blue blood at all... i thought it was either a dark red or a light red depending if it was haemoglobin or oxyhaemoglobin, has anyone seen blue blood?

[Mike]

do those people who say its blue think that white wine in a green bottle is green?

[leesmithg]

"

The color of blood comes from the red blood cells (RBC's, also called

erythrocytes), which make up about 40% of blood, by volume. Each red blood

cell is filled with hemoglobin, the protein which carries oxygen to tissues

and carbon dioxide away from tissues. Hemoglobin carries oxygen by using

heme, a large ring-like molecule which has at its center a single atom of

iron, which is what actually binds to the oxygen.

The nature of heme that gives it these abilities is in the many double

covalent bonds that form the ring.  These double bonds can be shifted into

many different configurations...

When oxygen binds to the iron atom in heme, the iron changes its shape

slightly, which alters the resonance of the heme molecule. This new

resonance gives off a different frequency of light, so the perceived color

of the heme goes from dark red to bright red. When the oxygen is released

into the tissues, the iron goes back to its original shape, and the heme

returns to its normal resonance, so the color goes back from scarlet to

maroon.

"

i googled because i am stupid and didnt know

585854038[/snapback]

Well red blood has oxyhaemogloben hence oxy as in saturated with oxygen.

[+E.Worm Jimmy Subscriber¹]

do those people who say its blue think that white wine in a green bottle is green?

585856176[/snapback]

lol probably. only a complete idiots actually belive that real blood can be blue.

[emo]

null vote, since both are right.

[505]

As said, blood is always red, but 'blue blood' is a phrase, meaning of royal blood. As for an explanation:

Unlike so many other expressions, this one is well documented. It?s a direct translation of the Spanish sangre azul. Many of the oldest and proudest families of Castile used to boast that they were pure bred, having no link with the Moors who had for so long controlled the country, or indeed any other group. As a mark of this, they pointed to their veins, which seemed bluer in colour than those of such foreigners. This was simply because the blue-tinted venous blood showed up more prominently in their lighter skin, but they took it to be a mark of their pure breeding. So the phrase blue blood came to refer to the blood which flowed in the veins of the oldest and most aristocratic families. The phrase was taken over into English in the 1830s.

[caerma]

of course is red... :doctor:

[red.]

i was taught that it was different types of red depending on whether it is oxygenated or not.

[phybre5]

not all arteries carry oxygenated blood though

arteries are away from heart, veins are toward, nothing really to do with oxygen

585853991[/snapback]

Excellent point. The pulmonary artery carries deoxygenated blood to the lungs, and the pulmonary vein carries oxygenated blood to the heart.

It is the veins that *appear* blue because the deoxygenated blood in them is dark red and the skin diffuses the colour or something.

585856098[/snapback]

I'm only explaining this here because this is the top google hit for this subject. Sigh.

Veins are typically closer to the surface of the body than arteries. Thus, you're not likely to see an artery at all without making an incision. But if you did, the artery could just as easily appear blue as a vein does.

Why are veins closer to the surface? A whole bunch of reasons. I would argue that the most important reason is that an organism is more likely to survive a venal rupture than an arterial rupture, so the veins were placed in the more vulnerable position instead of the arteries. Natural selection, etc. Organisms with shallow arteries didn't survive to reproduce.

Veins appear blue because they're a certain depth beneath the skin. They just happen to be at such a depth that only the most energetic visible light (blue) can penetrate and reflect back. All lower energy wavelengths are insufficient to the task.

If the veins were closer to the surface they'd be more white-shifted. If they were deeper they'd be more blue-shifted until they finally wouldn't be visible because no visible light has enough energy to get back to your eyes through all that skin. Which is exactly why you can't see your own organs through your skin, or pretty much anything deeper than veins.

Of course, other EM radiation can still penetrate and reflect. If you could see into the UV spectrum you'd be able to see deeper into your own body. If you could see all the way up to x-ray... well you already know that penetrates everything in the body except bone (and a small part of the brain). IR is on the opposite side of the visible spectrum, so being able to see only in IR would actually decrease your ability to see into your body. A lot of people think that IR goggles allow one to see inside bodies, but in fact what you're seeing when you look at someone with IR vision is their radiant heat. External heat signature. Every living thing emits certain amounts of radiation. To a lesser extent, all matter also does. Emits, mind you. Not just reflects. The interchange of energy in such ways is precisely what makes life possible in the first place.

The vein itself isn't blue. You're just seeing blue. As far as I know, nothing in the body is blue when directly viewed, free of all obstacles. But I could be wrong. Some muscle tissue might be a likely candidate.

The fact that deoxygenated blood is slightly darker than oxygenated blood has no bearing whatsoever on the blueness of your veins through the skin. It's the exterior wall of the vein that is being reflected. Not the contents of the vein. If the vein were full of water, alcohol, heroin, monkey paste, or nothing, it would still be visibly blue.

That's pretty much it.

If you want to talk about weird anatomical factoids, consider:

25% of humans across the world are missing tendons in their arms or legs (like palmaris longus or plantaris)

that number seems to be increasing over time

[Nelsinho]

:laugh: at least in humans is red LOL :laugh: :laugh:

[Cody]

blood is always red, just to support other posts in this thread. it only looks blue some of them time in your veins but its red.

[sto110]

red with o2 blue without

[seafirex]

blue but when air get in touch with it reacts to it by turning red. i was told that by a doctor but anyway he might have been wrong

[HoochieMamma]

red with o2 blue without

585977291[/snapback]

No, just darker if it doesn't have any oxygen. Blue is if the blood is based on copper and not iron.

edit: wait a sec wouldn't copper make it green? what metal based blood would be blue?

[AnakinSolo2002]

all the scientific sources are saying that it's "oxygen POOR blood" that is the dark red, so what if it had NO oxygen in it whatsoever? I bet you it would be blue.

[Sarm]

Blue blood! LOL !!!

My god there's some dumb answers here!, either I'm missing the sarcasm or they're posted by some stupid people!

[Krudomanic]

Its RED... and I have a simple explanation why this looks blue below which I hope will answer and close this case once and for all...

Veins carry dark red blood, and the vessels themselves are transparent, why is it that in the arms, hands, and legs of fair-skinned people they nonetheless look blue?

Fair skin normally reflects most of the light that hits it. Longer, redder wavelengths, though, can penetrate more deeply into the skin than shorter, bluer wavelengths before reflecting out. A vein looks blue because red light travels far enough into the skin to be absorbed by the blood in the vein. If the blood vessel is far enough below the skin, however, blue light--which would normally also be absorbed by the vein--reflects out of the skin before reaching the vein. So the light reflecting from tissue over the vein contains less red light than blue, giving the vein a bluish cast.

I hope this answers your question... :yes:

[yanowhiz]

Trust me I know, blood is red. I've had so many scabs from when I was really little.

[exotoxic]

blood is ALWAYS red :yes:

go put an elastic band around your finger (to stop the circulation) and you will see it turns blue/purple because no blood can get to the end of the finger

edit: you could then prick your finger and tell us if the blood that is left (im sure there would be abit still in?!?) is blue or not :laugh:

[Bobster]

Oxygenated blood is RED, dioxygenated blood is BLUE.

[exotoxic]

Ever wondered why blood vessels appear blue? Oxygenated blood is bright red: when you are cut, the blood you see is brilliant red oxygenated blood. Deoxygenated blood is deep purple: when you donate blood or give a blood sample at the doctor's office, it is drawn into a storage tube away from oxygen, so you can see this dark purple color. However, deep purple deoxygenated blood appears blue as it flows through our veins, especially in people with fair skin. This is due to the way that different colors of light travel through skin: blue light is reflected in the surface layers of the skin, whereas red light penetrates more deeply. The dark blood in the vein absorbs most of this red light (as well as any blue light that makes it in that far), so what we see is the blue light that is reflected at the skin's surface. Some organisms like snails and crabs, on the other hand, use copper to transport oxygen, so they truly have blue blood.

http://www.rcsb.org/pdb/newsletter/2003q2/mom.html