What documents do I need to present to reenter the United States? If seeking to enter the United States after temporary travel abroad, you will need to present a valid, unexpired âgreen cardâ (Form I-551, Permanent Resident Card).
Brain Tour. 2. Supply lines. Your brain is nourished by one of your body's richest networks of blood vessels. With each heartbeat, arteries carry about 20 to 25 percent of your blood to your brain, where billions of cells use about 20 percent of the oxygen and fuel your blood carries. When you are thinking hard, your brain may use up to 50 percent of the fuel and oxygen.
Veins, arteries, and capillaries are the 3 types of blood vessels. Arteries are the type of blood vessel that carries oxygenated blood from the lungs and heart out to the different parts of the body.From there, the capillaries take the oxygenated blood very close to where the blood is supposed to go.The red blood cells then pass the oxygen to the part of the body.The blood cells then go into the veins, which carry the blood back to the heart and lungs to be re-oxygenated. Basically, arteries carry blood from the heart, then the veins carry it back.he red blood cells then pass the oxygen to the part of the body. The blood cells then go into the veins, which carry the blood back to the heart and lungs to be re-oxygenated. Basically, arteries carry blood from the heart, then the veins carry it back.