There are two kidneys in the body, and they are located on either side of the vertebral column between the thick muscle of the back and abdomen. Each kidney is about 10 cm. long, 6 cm. wide, and 4 cm. thick. Each one weighs about 140 gm.
The major function of the kidneys is to remove waste products from the body by producing urine. They have about 1 million microscopic unit called nephrous. Their function is to receive and filter all the blood in the body once every 12 minutes. They remove waste products from the blood and return useful substances to the circulation. In this way, they enable the blood pressure to remain stable