KIDNEYS

Either of two bean shaped excretory organs that filter wastes from the blood and excrete them and water in urine and help to regulate the water, electrolyte, and pH balance of the body. The kidneys are located in the dorsal part of the abdominal cavity, one on each side of the vertebral column. Each kidney contains one million or more filtering units, called nephrons. Blood passes through where it is filtered; some substances (e.g., sugar, some salts) are selectively reabsorbed into the body. The final product known as urine passes out of the kidney is carried to the bladder. The function of the kidney is controlled by hormones. The kidney is subject to inflammation, infection and the formation of stones as well as other disorders.