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.
When blood enters the smallest blood vessels, which are called capillaries, and are found in body tissue, it gives nutrients and oxygen to the cells and takes in carbon dioxide, water, and waste. The blood, which no longer contains oxygen and nutrients, then goes back to the heart through veins.he heart pumps the blood and the arteries and veins transport it. Oxygen-rich blood leaves the left side of the heart and enters the biggest artery, called the aorta. The aorta branches into smaller arteries, which then branch into even smaller vessels that travel all over the body.