Drawing blood samples, ratio of oxygen to blood?

Question

If the blood is blue and you draw blood sample from veins or arteries....exactly how much oxygen in ratio to the amount of blood for it to turn red? Seems to me, Ive drawn blood before and there doesnt appear to be much oxygen involved in the process.

Answer 1

The blood in arteries is red anyway because it has oxygen in it from the air you breathe. If thet draw blood from your veins, it comes out red because even though it doesn't seem like there is much oxygen coming in contact with the cells, there is.