If blood flows through the heart twice for completing one circulation, it is called
If blood flows through the heart twice for completing one circulation, it is called double circulation.The majority of mammals (including humans) utilize a double circulatory system. This means that we have two loops in our body in which blood circulates. One is oxygenated, meaning oxygen rich and the other is deoxygenated which means it has little to no oxygen but a lot of carbon dioxide.