500
The path in which blood will flow from the body, heart, and lungs.
What are:
-Blood enters the right atrium of the heart from the body carrying carbon dioxide
-It's then pumped into the right ventricle where it leaves the heart and travels into the lungs
-Inside the lungs, carbon dioxide is exchanged for oxygen
-It then travels to the left atrium and is pumped into the left ventricle, where it travels back to the body