Nephrology.

Nephrology is the branch of medicine that deals with the function of the kidneys. As a consequence, a nephrologist frequently deals with problems related to homeostasis, that is, the maintenance of the internal environment of the body. The most obvious function of the kidneys is their ability to regulate the excretion of water and minerals from the body, at the same time serving to eliminate nitrogenous wastes in the form of urea. While such waste material, produced as by-products of cell metabolism, is removed from the circulation, essential nutrients from body fluids are retained within the renal apparatus. These nutrients include proteins, carbohydrates, and electrolytes, some of which help maintain the proper acid-base balance within the blood. In addition, cells in the kidneys regulate red blood cell production through the release of the hormone erythropoietin.