X mun( oomiB9@@e Solution Answer: The image represents the heart, the aorta and pulmonary vein have been labeled. The function of aorta and pulmonary vein have been discussed below: Aorta: The artery is the main artery of the body. It begins at the top of the left ventricle of the heart. The aortic valve opens and close in response to each heart beat to facilitate unidirectional flow of blood. Structurally, it consists of 3 layers: intima (inner layer), media (middle layer) and advetitia (outer layer) The main function of aorta is carrying oxygen rich blood from the heart to the rest of the body. Pulmonary vein: These are large blood vessels that receive oxygenated blood from the lungs and drains the oxygenated blood into the laft atrium of the heart. The structure of pulmonary have consists of the same 3 layers found in arteries, i.e, tunica externa/advetitia (thick layer of connective tissue), tunica media (smooth muscles) and tunica intima (endothelial cells). They contain valves to facilitate unidirectional blood flow..