Excretion is the removal of bladderrenalskinsweattwoureauretersurethrawastewater from the body. The body's excretionary organs are the bladderrenalskinsweattwoureauretersurethrawastewater, the lungs and the kidneys. The skin excretes water and salts as bladderrenalskinsweattwoureauretersurethrawastewater. The lungs excrete carbon dioxide and bladderrenalskinsweattwoureauretersurethrawastewater. The kidneys excrete water, salts and bladderrenalskinsweattwoureauretersurethrawastewater. The urinary system consists of bladderrenalskinsweattwoureauretersurethrawastewater kidneys, bladderrenalskinsweattwoureauretersurethrawastewater arteries and veins, ureters, bladder and urea. Blood enters the kidneys through the renal artery where bladderrenalskinsweattwoureauretersurethrawastewater, salts and urea are removed and form urine. The urine then passes to the bladderrenalskinsweattwoureauretersurethrawastewater via the bladderrenalskinsweattwoureauretersurethrawastewater. In the bladder, the urine is stored until it is removed from the body via the bladderrenalskinsweattwoureauretersurethrawastewater. The kidneys also control the amount of bladderrenalskinsweattwoureauretersurethrawastewater in the body.