Identify the parts of the circulatory system in the diagram.

The correct labels are described below:

a) Heart

b) Aorta

c) Common iliac vein or  Vena Cava

d) Blood Capillaries

The circulatory system can be described as the system, which controls the circulation of the blood in the body. the heart is the central organ of the circulatory system, which pumps the oxygenated blood to the body and receives deoxygenated blood from the body. The heart also sends the deoxygenated blood to lung for oxygenation and receives oxygenated blood from lungs to pump in the body.

IN general, the red color is used to depict the oxygenated blood and the blue color is used to depict the deoxygenated blood. The arteries are the vessels, which carry the blood away from heart and carry oxygenated blood (exception-pulmonary artery, which carry deoxygenated blood). The veins are the vessels, which carry the blood to the heart and carry deoxygenated blood (exception-pulmonary vein, which carry oxygenated blood). The arteries at the site of blood exchange, get branched into very thin vessels, which are known as capillaries, the other side of capillaries is joined to the veins.

The aorta is a large artery, which takes away blood from heart and branches into many arteries. The arteries and the veins, which supply the blood to iliac region and lower body part are known as common iliac artery or vein. The common iliac vein with hepatic portal system forms a common vein called as venacava.

In the label a, the vessel coming out of the heart shown is the pulmonary artery.