Kidneys Royalty-Free Stock Image

There are two bean shaped kidneys in the human body. A normal kidney is about 2.5 cm thick, 10 cm long and 5 cm wide. They are reddish-brown in color and each weighs approximately 130 gm in adults. Both kidneys receive blood from the renal artery; in a resting adult approximately 1.2 to 1.4 Litres of blood flows through both kidneys in one minute which means every 4 to 5 minutes all the circulating blood in the body passes through the kidneys. Kidneys help remove excess salt, water and waste products from the bloodstream. Like other endocrine organs, kidneys also secrete important hormones such as rennin and erythropoietin into the circulation. These hormones play significant roles in the production of blood cell and in the regulation of blood pressure.