To study the sequence of microscopic changes occurring during development of kidney in 12wk-35wk human fetuses

Study the sequence of microscopic changes taking place during development of kidney in human foetuses. Aborted fetuses were studied after measuring external parameter such as CRL. After undergoing tissue processing, microscopic structure of each kidney was observed after H&E staining. For analyzing various stages of development of glomeruli different groups were made and changes observed. During 12 to 14 weeks undifferentiated mesenchyme was seen increasing in amount from outer to inner hilar aspect. Transition zone appeared between cortex and medulla at 16-18 weeks. At 22 wk tubules differentiated as proximal & distal convoluted tubules. Longitudinally running collecting ducts can be appreciated at 22-27 wk, medullary rays are seen at 29 wk. Undifferentiated mesenchyme continue to appear till 35 wk.We found that nephrogenic zone was present immediately beneath the capsule; glomeruli were seen at different stages of development. S shaped tubules were observed at 20 – 24 weeks and C shaped and crescent shaped in later weeks of development.