Excretory System

The frog's excretory system removes nitrogenous waste and manages the body's salt and water balance through a pair of dark red, flattened, mesonephric kidneys lying on either side of the vertebral column, each packed with numerous nephrons. Because the main nitrogenous waste product excreted is urea, frogs are classified as ureotelic organisms (unlike the uric-acid-excreting, uricotelic cockroach and pigeon). A pair of ureters carries this waste from the kidneys to the cloaca, and a thin-walled, unpaired urinary bladder, l …