【摘要】 本研究对14～28周5例胎儿肾脏的发生进行了光镜和透射电镜的观察。观察到肾单位的发生是由皮质深层向皮质浅层逐渐演化。皮质深层的肾小体较为成熟,形态结构与成年者相似。浅层为正在发育的原始肾小体。原始肾小体的毛细血管原基为间充质细胞团,在原始球囊的凹陷中逐渐分化成原始毛细血管,其内皮较厚,无孔亦无明显的基膜。较成熟的毛细血管才有明显完整的基膜。原始肾小体的足细胞为紧密排列的柱状细胞团,细胞之间有紧密连接和桥粒。此连接随细胞形态的改变而发生位置转移,并且是暂时的结构,当初级突和次级突形成后此连接相继消失。各肾小管的结构与所见文献报道相似。在28周胎儿肾脏中发现一未分化的肾小管,腔内有大量纤毛断面和脱落细胞碎片,其纤毛中微管排列为“7+1”、“6+1”及“5+1”不等。更多还原

【Abstract】 The structure of 5 human fetal kidneys in the age between 14～28 weeks were observed under light and transmission electron microscope. The results were summarized as follows:The whole developmental process of the renal corpuscle may be revealed from the subcapsular cortex to the juxtamedullary region. The glomeruli in the deepest part were the largest, well developed, and more similar to those of the adult, while those in the subcapsular cortex were just beginning to differentiate. The cup shaped primary renal capsule was occupied by a cluster of mesenchyma, the primodium of the glomerulus. The capillary of the glomerulus was directly differentiated from its primodium, contrary to the traditional concept that the cap shaped renal capsule was formed by the invading capillary sproutings of the interlobular artery against the bulblike end of the primary renal tubule. The endothelium of the primary capillary was usually thicker than that of the adult, ones, there were many irregular processes projecting to the lumen, and pinocytotic vesicles were not infrequently revealed, nevertheless fenestrations and basement membrane were not yet recognized in this period. The basement membrane developed from incomplete patches into continuous one subsequently and became obvious at a later stage.The primodium of the capsule of the renal corpuscle was a cluster of cells densely arranged as columnar epithelium. Intercellular junctions such as tight junctions and desmosomes were located on the middle region of its lateral cell membrane, as the visceral epithelium flattened by the compression of the growing glomerulus, they varied in form and location and subsequently disappeared when the epithelial cells transformed into mature podocytes.As for the developmental morphology of various renal tubules were similar to those reported before, however, in one of the undifferentiated renal tubule of the 28-week fetal kidney, debris of exfoliated epithelial cell and large amount of unusual cilia with 5,6, or 7+1 microtubules instead 9 doublets+one central pair microtubules were revealed in its lumen.更多还原