a scientific question

  1. My daughter asked me this question the other night as she looked at the blue colored veins running down her arm..."If a person's venous blood is blue, and turns red when exposed to oxygen, (hence the red blood when cut); then, if a person were cut in an area devoid of oxygen (venous cut) would they bleed blue blood?" Logically, this makes sense (to her), but would this be true scientifically?
  2. 2 Comments

  3. by   oramar
    But venous blood is a lot darker than arterial blood, my guess is that venous blood still has some oxygen in it and that is why it is not blue. By the way most nurses have drawn arterial blood and seen that same dark color, it causes our hearts to sink. It means that the patients gases are going to be bad and is in every bit as much trouble as we feared.
  4. by   Stargazer
    Oramar's right. Normal arterial blood should have 95 - 100% oxygen saturation. Normal venous blood will still be about 50 -70% saturated.

a scientific question