Observe the illustration of the lungs, the heart, and body parts.

Copy the illustration and connect the lungs and body parts to the heart using lines. Also, show the route of blood flow.

The human circulatory system follows double circulation pattern, where the same amount of blood crosses the heart twice, per cycle, for the transport of oxygen. The two parts of circulation are :

1. Pulmonary circulation: In this, the deoxygenated blood from the right atrium, reaches the lungs with the help of pulmonary arteries. Here, the blood gets oxygenated by the inspired air present in lungs and then moves back to the heart, in the left atrium through pulmonary veins.

2. Systemic circulation: In this, the oxygenated blood from the left atrium, moves to left ventricle, from where it is supplied to all the other body organs via the aorta. In the tissues of the organs, the oxygen gets diffused out, because of difference in pressure, and the deoxygenated blood is carried by the veins, majorly the inferior and superior vena cava to the right ventricle of the heart. This blood is given back to the right atrium, from where it undergoes pulmonary circulation again.

Thus, blood gets oxygenated in the lungs and is then pumped to the whole body by the heart, with the help of blood vessels.