Medically reviewed by Michael Menna, DO Key Takeaways The body's organ systems include your circulatory and respiratory ...

Your circulatory system is how your oxygen-rich blood flows from your heart through your body, washing over all your vital organs, then returning oxygen-poor blood to your heart.

What are the differences between arteries and veins? Read on to find out about these blood vessels, plus other types, and how the cardiovascular system works.