This document provides information about the anatomy and physiology of the human renal system. It describes the structure and function of the kidneys, nephrons, ureters, bladder, and urethra. The kidneys filter the blood to remove wastes and regulate fluid levels. The nephrons are the functional units of the kidneys that filter blood and selectively reabsorb or secrete fluids and solutes to produce urine. Urine is then transported through the ureters to the bladder for storage and later excreted through the urethra.