How is urine produced?
Urine is the product of filtration of blood by the kidney; it is a watery solution of waste products, salts, organic compounds, and two important nitrogen compounds: uric acid and urea. Uric acid results from the decomposition of nucleic acids, and urea results from the breakdown of amino acids in the liver. These nitrogenous compounds are harmful to the body and hence must be removed from the body.