Explain how deoxygenated blood travels from body to lung for purification.
The deoxygenated blood from the various parts of the body is collected by the veins which transport the blood to the heart through the vena cava. Vena cava pours the deoxygenated blood in the right atrium of the heart. The right atrium contracts and the blood moves into the right ventricle. On contraction of the right ventricle the deoxygenated blood is transported to the lungs through the pulmonary artery for purification.