Urine Formation
The end product of all this nephron activity is the formation of urine. Urine is made mainly of water, and contains nitrogenous wastes such as urea and uric acid, salts and metabolites from endogenous (ie those produced by the body) and exogenous sources (ie drugs).
A healthy adult will produce over a litre of urine every day. The pH will range from 4 to 8.5. These figures will dramatically vary depending on many factors such as fluid and salt intake, environmental temperature, and the presence of disease or use of medication.