Colour of veins

[Blueberrysplash]

I've often noticed that the veins in our hands are a bluish-greenish colour. All I want to know is why is that so? Is it due to the presence of a certain coloured pigment in the walls of the vessel?

Thanks!!

[Chroma]

Deoxygenated blood is actually a blue color, its just that you never see it unless its in the veins through the skin. If you were to cut yourself then the blood that pours out, even from a vein, is quickly saturated with oxygen from the atmosphere as the Hemoglobin is so efficient at absorbing it.

In a vacuum or in an atmosphere without oxygen deoxygenated blood would remain blue.

[Swede]

Are you sure? As far as I know venous blood is dark red. The blue colour of veins are due to the skin which acts as a filter of light, letting blue colour pass. The veins themselves are white and the deoxygenated blood is dark red. Even if some diffusion happen when venous blood get in contact with air this diffusion isn't enough to saturate all of the hemoglobin.

[jwalin]

wow
i think both of you are right
anything could be right


but to just give another veiwpoint
fe 2+ ions are blue green. and when they take up oxygen they form fe 3+ red in color.

[Swede]

If you have ever taken a blood samle you know that the bottles in which you collect the blood are vacuum isolated. In other words, the blood never get in contact with air at all (almost).

[jwalin]

even my textbook says the veins look blue but the blood is dark red