Dear friends, Please read our latest blog post for an important announcement about the website. ❤, The Socratic Team

When viewing a picture of the circulatory system, what do the red and blue blood vessels mean?

1 Answer
Write your answer here...
Start with a one sentence answer
Then teach the underlying concepts
Don't copy without citing sources


Write a one sentence answer...



Explain in detail...


I want someone to double check my answer

Describe your changes (optional) 200

Feb 10, 2016


Red = oxygenated blood
Blue = non - oxygenated blood


Correct me if I'm wrong, but I believe the blue blood vessels are to identify the veins in your circulatory system, carrying non-oxygenated blood back to the heart (because the oxygen has been diffused to the cells by capillaries for cellular respiration).

The red blood vessels represent the arteries, they carry the oxygenated blood (starting from the aorta) to the entire body, the oxygen being diffused by the capillaries as well.

Blood becomes oxygenated thanks to gas exchange ( CO2 and O2) in the lungs.

Was this helpful? Let the contributor know!