Quantitative investigations on the topography of twelve structural elements of the male gonad.

For elucidating the problem whether the tissue composition of the male gonad is identical or different in the equatorial zone and polar zones of the organ, 104 left testes were studied obtaining them from the cadaver of patients dying from various acute and chronic diseases not affecting the endocrine system. In the histological preparations of the polar and equatorial zones of the testis, the proportion [%] were calculated of 6 types of convoluted tubules designated with numbers from 1 to 6 in the sequence of decreasing spermatogenic activity, and by the morphometric method, the proportions [%] were determined of the tubular lumina, spermatogenic epithelium, tubular membrane, stroma, blood vessels, and LEYDIG's cells. In the whole analysed group, only tubules type 2 were more numerous in the equatorial part, while tubules type 6 prevailed in the polar parts. The lumina of the tubules occupied a greater % of the testicular structure in the polar parts as compared with the central part. Other tissue elements were present in similar amounts or the differences between their amounts in these parts were only nearly significant statistically. The study showed also that the number of type 1 tubules decreased significantly with progressing age, while the number of type 6 tubules increased. A statistically significant fall of the proportion [%] of the spermatogenic epithelium and increased proportion of tubular membranes and stroma were another age-related changes. It is worth stressing that these age-related processes progressed parallelly in the equatorial part and in the polar parts of the testis which suggest that ageing of the organ occurs simultaneously in the whole gonad.