Histogenesis of Male Gonads in Developing Human Foetuses
DR. PHAD VAIBHAV V.DR. Mrs. JOSHI RAJNI A. DR. JADHAV SHAILENDRA S. DR. HEREKAR NARSINH G.
The male Gonads or Testes are embryologically derived from mesoderm except for Primordial germ cells giving rise to spermatogonia which are derived from epiblast. The true sources are the mesothelium lining the posterior abdominal wall, underlying mesenchyme & Primordial germ cells. The gross changes occurring during development of male gonads are studied in much more detail as compared to histological changes therefore very few studies available on the same. 40 aborted male human fetuses between 12- 40 weeks of gestational age with no obvious congenital anomalies were obtained for study. Testes were removed and histological slides of 5 to 7 microns sections were
prepared and stained with Haematoxylin and Eosin method. Also some slides were stained with Massons trichrome stain & studied under light microscope. The tunica albuginea & epiorchium were already
differentiated at 12th week of gestational age. Tunica vasculosa appeared at 14th weeks of gestational age. At 16th week some rete tubules were seen in mediastinum. At 24th weeks of gestational age complete septae were seen, and the lobules were completely formed. At 28th week both layers of tunica vaginalis were seen. Initially dark nucleated spermatogonia were more numerous than pale nucleated spermatogonia and Sertoli cells. After 30th week pale nucleated spermatogonia were more numerous along with Sertoli cells. The findings also showed that testis at term were not assuming adult architecture. The seminiferous tubules were showing absence of cells of spermatogenic series. They seem to appear at puberty, and lumen in these tubules does not appear till term.