. What is meant by double circulation? What is its significance
In mammals left part of the heart contains oxygenated blood and the right part of the heart contains deoxygenated blood. Thus blood passes two times in one complete circuit – one with oxygenated blood and another with deoxygenated blood. This type of circulation, which takes place twice but in the same time separately is known as double circulation.
This double circulation system prevents mixing of oxygenated and deoxygenated blood with each other which usually happens in amphibians or fishes.
When blood goes through the heart twice, it is known as double circulation. For example, in our bodies we have double circulation. Dirty blood enters the heart first through vena cava and then is sent through the pulmonary artery to the lungs. Then purified(oxygen-rich) blood enters the heart for the second time to be pumped to the whole body.
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