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 take blood to the heart, arteries take blood away from the heart. The vessels that carry blood to the heart are called veins. Those that supply the body with blood â¦ from the heart are called arteries.Examples are the jugular veins that return blood from the head, and the carotid arteries that supply blood to the head.wo other heart valves separate the ventricles and the large blood vessels that carry blood leaving the heart.