The correct sequence of circulation of blood in the human body is:
We must be aware that the lungs supply oxygenated blood to the left atrium of the heart. Gradually, it contracts and blood is allowed to enter the next chamber (the left ventricle) as it expands. When the left lower chamber of the heart contracts, blood is pumped into the body through the aorta. Oxygenated and deoxygenated blood is easily separated by the heart. Deoxygenated blood from the body reaches the upper chamber of the right atrium of the heart and it expands. This transports the blood to the right ventricle, which in turn pumps it to the lungs for oxygenation.