the organ that performs filtration of blood, reabsorption, and secretion in vertebrates is the _______.
For other uses, see Kidney (disambiguation). The kidneys are two bean-shaped organs found on the left and right sides of the body in vertebrates. They filter the blood in order to make urine, to release and retain water, and to remove waste (The excretory system). They also control the ion concentrations and acid-base balance of the blood.