[stana (OP)]

Ive heard blood inside me is blue? But howcome whe it comes out its red? I was told its cause it mixes with the oxygen..but howcome when i go to the doctors and they withdraw blood, its red inside the needle?


thanks

[Karen W.]

We have all heard that, but blood is never blue! It only looks that way through your skin and veins, because your veins are a whitish blue in color and have thin walls! The blood is a darkish red and light does not reflect well through it! Now when you cut yourself you usually see venous blood,(from a vein and not an artery) that drips out and is pretty bright red.

My Blood has often been so dark red it looked black at the time of the draw.. it was weird!

Now the Arteries look less blueish and are a tiny bit whiter,and are a bit thicker walled then a vein in order to handle the a high pressure system that pumps the blood through them. This is what your doctor or you can feel when you check your pulse. That bumping is an artery pulsating to the rhythm of your heartbeat. So if you cut an Artery it would pump blood out in the rhythm of your heart beat, yet the blood will still be dark red. You do not want to cut your artery ever..You bleed out a lot faster and be in Danger quickly!Picking up oxygen can brighten the bloods color some but, it is still red!

[stana (OP)]

aaah i get it now. Thanks!

[Karen W.]

Your welcome.

[paul.fr]

I though you could have 'blue blood' if you had Wilson's disease...something to do with too much copper...

any way, found this
http://www.thenakedscientists.com/forum/index.php?topic=1038.msg8990#msg8990

[Karen W.]

Really!I had never heard that.. I will look! Thanks Paul.

Well I found nothing about "Wilsons disease"  in those posts, but that other Animals like lobsters crabs and shrimps, crustacea have blueish blood, but not humans.