Kidneys are a filter system. The main job of the kidneys is to remove waste from the blood and return the cleaned blood back to the body. Each minute about one litre of blood ï­ one-fifth of all the blood pumped by the heart - enters the kidneys through the renal arteries.
The volume of helium in the balloon has been estimated as being able to lift a total load, including the balloon material and the structure beneath it, of 65 pounds (29 kg) at sea level and 48 pounds (22 kg) at 8,000 feet (2,400 m).
balloon - large tough nonrigid bag filled with gas or heated air. 1  gasbag, envelope - the bag containing the gas in a balloon. 2  hot-air balloon - balloon for travel through the air in a basket suspended below a large bag of heated air. 3  lighter-than-air craft - aircraft supported by its own buoyancy.