Fig. 10

View onto the occurrence of erythrocytes in the fetal human kidney during advanced pregnancy by the optical microscope. The specimen stained by Azan depicts that microvessels perfused by erythrocytes are restricted to the district of progenitor cell recruitment (DPCR, black arrow heads) of the nephrogenic zone and the maturation zone (MZ, white arrow heads). In contrast, in the area of nephron shaping (ANS) including the vertically lining perforating radiate artery (PRA), the occurrence of erythrocytes is not observed. C renal capsule, CD differentiating collecting duct tubule, T tip, H head, C conus of the A collecting duct ampulla, PTA pretubular aggregate, RV primitive renal vesicle, CNT connecting tubule, SSB S-shaped body