now those are arteries, that's the pulmonary artery  but it's coming back to the heart  okay, that's the only time you're going to find the rule reversed, arteries leave the heart, veins come back to the heart, and the only time that rule is reversed is when you're linking the heart and the lungs through the pulmonary vein and the pulmonary artery, however, they are still carrying, the arteries are still carrying oxygen charged blood, yes, because it's come fresh from the lungs so it's still carrying nice red lovely oxygenated blood, yes, even though it's coming back into the heart, that is because it's come fresh from the lungs and the vein although it's going in the opposite direction the way you normally expect it, is still carrying the old rotten, you know, used up blood, because it's going back to the lungs to be recharged, do you understand it alright?