Aluminum Grades Series 7xxx. Zinc, in amounts of 1 to 8% is the major alloying element in 7xxx series aluminum alloys (7075, 7050, 7049, 710.0; 711.0 etc.), and when coupled with a smaller percentage of magnesium results in heat-treatable alloys of moderate to very high strength.
We previously learned that arteries carry blood away from the heart and that veins carry blood toward the heart. This idea holds true here because we see that the pulmonary arteries are carrying blood away from the heart and the pulmonary veins are carrying blood to the heart. The interesting thing is that in most areas of the body, veins carry blood that is low in oxygen and arteries usually carry blood that's rich in oxygen.
The circulatory system is made up of the heart and blood vessels. The heart pumps oxygen-rich blood through vessels called arteries. Veins carry blood from various parts of the body back to the heart. Arteries and veins are connected by tiny capillaries (KAP'ih-laireez). The heart's right side receives dark bluish blood from the superior and inferior vena cava. (The superior vena cava is the large vein that brings blood back from the upper part of the body. The inferior vena cava is the vein that brings blood from the lower body.) The heart's right side pumps this blood to the lungs. There, waste gas (carbon dioxide) is removed and oxygen is picked up. The bright red oxygenated blood returns to the heart's left side.