Describe double circulation in human beings. Why is it necessary?
The circulation of blood in the Human heart goes as follows:
- The left atrium of the heart receives oxygenated blood from the lungs. It further moves down to the left ventricle.
- This blood is then pumped through the aorta to the entire body , to supply cells and tissues with oxygen.
- Oxygen poor blood (deoxygenated blood) from the various body parts, returns to the heart.
- This blood enters the right side of the heart, through the right atrium and passes down to the right ventricle.
- These collect and pump the deoxygenated blood to the lungs through the pulmonary artery. The lungs refresh the blood with a new supply of oxygen, making it
The valves in the heart ensure that the blood does not flow back .
- Oxygenated blood then again enters the left side of the heart, through the left atrium and left ventricle.
As we can see, blood flows through the heart twice in the same cycle. This is known as double circulation .
- Double Circulation ensures that oxygenated and deoxygenated blood are not mixed together.
- This means that human cells get a supply of pure oxygenated blood .
- This means more energy is produced which ensures higher efficiency.