The kidneys are the major excretory organs of the body.
The kidneys are two reddish brown organs situated high up on the posterior abdominal wall, one on each side of the vertebral column. The left kidney lies slightly higher than the right (because the left lobe of the liver is smaller than the right). Each kidney gives rise to a ureter that runs vertically downward on the psoas muscle.
With contraction of the diaphragm during respiration, both kidneys move downward in a vertical direction by as much as 1 in. (2.5 cm).
Function of Kidneys:
The two kidneys function to excrete most of the waste products of metabolism. They play a major role in controlling the water and electrolyte balance within the body and in maintaining the acid–base balance of the blood. The waste products leave the kidneys as urine, which passes down the ureters to the urinary bladder, located within the pelvis. The urine leaves the body in the urethra.