Anatomy and physiology of the kidney.

The kidneys are complex organs, and they are vital in maintaining normal body functions. A human being's survival depends, to a large degree, on the crucial functions and processes performed by the kidneys. The renal system affects all parts of the body by keeping body fluids in balance and other organ systems functioning normally. Renal and urologic disorders may strike anyone at any age and at any time. An estimated 20 million Americans are affected with renal disorders each year.