What is unique about the pulmonary veins and pulmonary arteries when compared to other veins and arteries on the body?

They are backwards: All arteries in the body carry oxygenated blood from the heart. After leaving the arteries, blood enters capillaries where oxygen is dropped off and carbon dioxide waste is picked up. Veins then take the carbon dioxide back to the heart. Now here is the difference. The pulm. Arteries then take the blood with carbon dioxide to the lungs where oxygen is picked up and carried by the pulm. Veins.