Male reproductive system secretions

The male reproductive system includes the two testes, ducts that store and transport the sperm to the exterior, and the glands that secrete into these ducts and the penis it also includes the hormones that integrate the reproductive activities. Basic details of the anatomy of the male reproductive system are given in Figures 19.1 and 19.2. 

Table 19.1 Compounds present in the secretions from various glands associated with the male reproductive system and their functions...

Testosterone is a steroid hormone molecule that is found in human males and females as well as many other species. In humans testosterone serves as the primary male sex hormone, and it plays a crucial role in the development of the male reproductive system. In males it is secreted from the tesisticles, and in females it is secreted from within the ovaries. Males use significantly more testosterone than females, and for this reason males produce testosterone at about twenty times the rate of females. Oddly enough, males are also less sensitive to testosterone than females. 

Self-referencing ion-selective electrodes have seen attractive applications in a diversity of medical problems. For example, the vacuolar-type H+-ATPase has been shown to play an important role in the acidification of the lumen of the proximal vas deferens, part of the male reproductive system. An acidic luminal fluid is required for the maintenance of sperm quiescence and for the prevention of premature activation of acrosomal enzymes during their storage in the epididymis and vas deferens. Proton secretion in the proximal vas deferens has been measured with the self-referencing technique (Fig. 6) [40]. Likewise, altered potassium homeostasis is indicative of dying cells, as the transplasma membrane potential is no longer maintained, as measured in both viable and nonviable embryos [41]. 

Endothelins interact with several endocrine systems, increasing the secretion of renin, aldosterone, vasopressin, and ANP. They exert a variety of actions on the central and peripheral nervous systems, the gastrointestinal system, the liver, the urinary tract, the male and female reproductive systems, the eye, the skeletal system, and the skin. Finally, ET-1 is a potent mitogen for vascular smooth muscle cells, cardiac myocytes, and glomerular mesangial cells. 

Supplementary information about the reproductive system is obtained in the same study to investigate the possibility of interference by the test Substance with the secretion and synthesis of steroid hormones of the male and female gonads. 

The male reproductive anatomy includes the penis, two testes, and a system of exocrine glands whose secretions form the seminal fluid. The exocrine glands consist of the two bulbourethral glands (Cowper s glands), two seminal vesicles, and the prostate. The bilateral ducts that connect this system and transport sperm and seminal fluid are the epididymis, the vas deferens, and the ejaculatory duct, which enters the urethra. 

Sexual differentiation of the central nervous system also occurs during fetal development, and it is equally fundamental to reproductive function during adulthood. Adult males exhibit a relatively continuous pattern of gonadotropin secretion from the hypothalamic-pituitary axis and are therefore fertile throughout their reproductive lifetime. In contrast, adult females exhibit a cyclical pattern of gonadotropin secretion and are fertile only during the transient period that follows ovulation during each reproductive cycle. This fundamental difference is due to irreversible... 

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