Thekidneysareorgansthat serve several essential regulatory roles invertebrateanimals. They are essential in theurinary systemand also servehomeostaticfunctions such as the regulation ofelectrolytes, maintenance ofacidbase balance, and regulation ofblood pressure(via maintaining salt and water balance). They serve the body as a natural filter of theblood, and remove wastes, which are diverted to theurinary bladder. In producingurine, the kidneys excrete wastes such asureaandammonium, and they are also responsible for the reabsorption ofwater,glucose, andamino acids. The kidneys also producehormonesincludingcalcitriol,erythropoietin, and the enzymerenin.
