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Embryology, Anatomy, and Physiology of the Male Reproductive System
Published in Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple, Basic Urological Sciences, 2021
Spermatogenesis occurs within the seminiferous tubules.Sertoli cells support germ cells and provide nutrition during the maturation process.Within tubules, germ cells are layered from the basement membrane to the lumen in order of differentiation.
Overview of Cryptorchidism with Emphasis on the Human
Published in Tom O. Abney, Brooks A. Keel, The Cryptorchid Testis, 2020
David R. Roth, Larry I. Lipshultz
Within each tubule lie the parenchyma of the testis consisting of the seminiferous tubules. There are an estimated 840 tubules per testis, each one with an average length of 70 to 80 cm and diameter of 0.12 to 0.30 mm. These tubules converge upon the mediastinum where they become less convoluted and join other tubules to form from 20 to 30 larger tubuli recti which are 0.5 mm in diameter. Within the mediastinum they coalesce to form epithelial-lined channels known as the rete testis. The rete testis terminate with 12 to 20 ductuli efferentes which perforate the tunica albuginea and proceed to the epididymis.
Mechanical Disease
Published in Jeremy R. Jass, Understanding Pathology, 2020
Only about 5% of newborn infants with this condition develop meconium ileus, but mis is life threatening without surgical intervention. In later life the most serious complications relate to the lungs and are due to plugging of the bronchi by mucus. Dilatation of the bronchi or bronchiectasis and severe lung infections follow. The mucus also blocks the ducts within the pancreas leading to loss of the glands that secrete digestive enzymes. The latter can be replaced artificially in the diet. Affected males are usually infertile because of obstruction of seminiferous tubules, and females may have anovulatory cycles as a consequence of chronic ill health.
The effect of melatonin on testis histological changes and spermatogenesis indexes in mice following treatment with dexamethasone
Published in Drug and Chemical Toxicology, 2022
Malek Soleimani Mehranjani, Mina Azizi, Firouzeh Sadeghzadeh
100 round seminiferous tubule cross-sections in each testis tissue were randomly selected under a light microscope. All spermatogenic and Sertoli cells were counted and spermatogenesis indexes including tubule differentiation index (TDI), Spermiogenesis index (SPI), meiotic index (MI) and Sertoli cell index (SCI) were calculated. The tubule differentiation index (TDI) is defined as the percentage of seminiferous tubules containing at least three differentiated germ cells (spermatocyte, round and long spermatid) from the B spermatogonia stage. To evaluate the SPI index, seminiferous tubules containing spermatozoa in their lumen were considered as the tubes with positive spermatogenic index and tubules without spermatozoa in their lumen were considered as the tubes with negative spermatogenic index. To calculate the MI, the number of round spermatid cells and the primary spermatocytes in each lumen were counted, and calculated based on the ratio of round spermatid cells to the primary spermatocytes and the SCI was calculated by dividing the number of the germ cells into the number of the Sertoli cells (Sadeghzadeh et al.2019).
Effects of Sargassum virgatum extracts on the testicular measurements, genomic DNA and antioxidant enzymes in irradiated rats
Published in International Journal of Radiation Biology, 2022
Ahmed I. Semaida, Mona A. El-Khashab, Abdullah A. Saber, Amal I. Hassan, Shady A. Elfouly
The testicle tissue mainly divides into two different parts which are directly affected by the radiation damage. First, the seminal tubes that makeup sperms. These tubes are very sensitive to radiation which may lead to permanent sterility due to the damage occurred in these structures. Second, Leydig cells which secrete testosterone and are relatively resistant to radiation. However, exposure to radiation may reduce the testosterone levels, decrease endurance, or depression (Nicholas et al. 2017; Farhood et al. 2019). It has been established that luteinizing and follicle-stimulating hormones (LH and FSH) regulate the testicular functions in the Leydig cells and Sertoli cells. LH controls testosterone production through its interaction with Leydig cells, as radiation-induced harm to Leydig cells prevents production of testosterone and also leads to a compensatory increase in LH levels. The Sertoli cells are located within the seminiferous tubules and play a role in spermatogenesis. The damage caused by radiation to these cells are well known to affect the sperm production and FSH may be increased (Dueland et al. 2003; Hermann et al. 2005). Generally, spermatogenesis is a long procedure taking 40–50 days in rodents. Manivannan et al. (2009) also highlighted that the seminiferous tubules become in an active development phase from 20 to 60 days, and the newly formed spermatogenic cells are arranged properly inside these tubules. At 60 days, all stages of spermatogenesis become clearly visible and spread in the lumen of the seminiferous tubules (Hassan and Alam 2014).
Microarray profiling of LncRNA expression in the testis of pubertal mice following morning and evening exposure to 1800 MHz radiofrequency fields
Published in Chronobiology International, 2021
Fenju Qin, Honglong Cao, Chuhan Feng, Tianyuan Zhu, Bingxu Zhu, Jie Zhang, Jian Tong, Hailong Pei
Hematoxylin-eosin (HE) staining results for testis acquired from the sham and RF groups mice are presented in Figure 2(a). In the sham groups, the seminiferous tubules within the testis showed good development; the diameter of the tubules was normal, there was good integration of the seminiferous epithelium, and evidence of normal spermatogenesis. The Leydig cells within the seminiferous tubules are normal in terms of their development and number. Following RF treatment, we observed that there was significant damage to the development of the seminiferous tubules and spermatogenesis. The diameter of the seminiferous tubule was smaller, and there was a lower number of cells in the seminiferous epithelium including (spermatogenic cells and sperm); there was also a lower number of Leydig cells that were also more immature. It was also evident that the extent of damage caused by exposure to RF in the morning (CT7:00) and the evening (CT19:00) showed marked changes. For example, mice that had been exposed to RF in the morning had no sperm cells and no mature sperm.