[Transformation of the kidney pelvis and the major and minor calices during their development]

The investigation has been performed in 28 series of histological sections of human embryos and prefetuses (4-20 weeks of the intrauterine development) and in 17 fetal corpses by means of certain histological methods, preparation of graphic reconstructive models, microscopy and fine preparation. The structural form of the definitive organ renal pelvis is demonstrated to depend on the ramification type of the metanephric duct derivatives. This is stipulated by interinductive processes of the ureteral sprout and metanephrogenic tissue. Quantitative and qualitative characteristics of the diverticulum ramification of the mesonephric duct during embryonic period of the prenatal ontogenesis predetermine the number of the calyces renalis majors and minors in the metanephros.