carbon dioxide from the air is used to produce glucose and other  compounds.
Blood Filtration in the Kidney. The kidneys filter about one-quarter (750-1000 pints) of the blood that is output by the heart daily. This blood is sent to the body's filter treatment plant, where it is purified by the kidneys and circulated on to the rest of the body. Some of the blood flow becomes fluid waste (1/1000th to 2/1000th) and is sent into the bladder for storage until it can be conveniently expelled. This toxic waste is called urine.
Human blood is composed of two essential elements: the liquid consisting of water, organic matter and minerals in the solid soluble and consists of cellular elements (red cells, white cells and platelets). In case the blood harvested from the patient's vein is placed in a test tube coagulates after a few minutes.