INTRODUCTION The term urogenital refers to something that has both urinary and genital origins. The word urogenital is used because the urinary and reproductive systems in males merge. These are grouped together because of their proximity to each other, their common embryological origin and the use of common pathways (ex. urethra). Kidneys and urinary ducts form the urinary system. The Urinary system performs two important homeostatic processes like excretion and osmoregulation. This system is intimately associated both anatomically, and in terms of embryonic origin with the genital system. The genital system includes the gonads which generate gametes and the genital ducts that serve as passages for the gametes. Though functionally different the two organ systems the urinary and the genital system are treated together as the urino- genital system, since both develop from the same segmental blocks of trunk mesoderm or adjacent tissues and share many of the ducts. Thus although the two systems have nothing common functionally they are closely associated in their use of common ducts and are studied under the broad heading of urinogenital system. The function of the excretory system is crucial in considering the possible environment of the ‘vertebrate life ’. Several main functions can be attributed to all vertebrate excretory systems: Excretion of nitrogenous waste products. Maintaining homeostasis with regard to ions (i.e. salt balance). Regaining valuable substances (glucose, salts, amino acids, etc.) Maintaining a physiological osmotic value (i.e. water balance). The excretory system is formed by a series of paired, segmental nephrons that begin with a nephrostome opening into the coelomic cavity. A pair of glomeruli per segment, supplied by branches from the aorta, projects into the coelomic cavity close to these nephrostomes. At a later stage of development, the glomerulus/nephrostome area becomes separated from the rest of the coelomic cavity by an epithelial fold. The nephrons connect to a duct that is formed by caudal growth of the most anterior nephric tubules. These paired urinary ducts open near the anal region.