Kidneys are the main excretory organ in humans. Kidneys are reddish-brown, bean-shaped structure situated between the levels of the last thoracic and third lumber vertebrae closer to the dorsal inner wall of the abdominal cavity. Each kidney is 10-12 cm long, 5-7 cm width, 2-3 cm in thickness. The average weight of the kidney is 120 to 170 gm