The brain is an essential part of the human body and has got structures and components that control body functions. The hypothalamus combines with other endocrine glands such as the pituitary glands and gonads in controlling the reproductive system (Dyer, 1989). The three glands work incorporation and there is no way one can work without the others. The three form a single system that affects all the reproductive cycles in the human body. The reproductive system of a human being is controlled by hormones that are normally generated by the three endocrine glands (Dyer, 1989). The hormones produced by these glands keep on fluctuating every time in order to have the desired effect on the reproductive system (Johnson, 2012). The hypothalamus is the origin of the entire process because it triggers other endocrine glands that control the reproductive system to start playing their roles (Johnson, 2012). This paper will highlight how the brain structures govern the timing and cycles of reproduction in humans.
The hypothalamus is responsible for secreting the Gonadotropin-Releasing Hormone which is commonly referred to as GnRH. The hormone initiates all the reproductive cycles in the human body (Johnson, 2012). The GnRH then travels through the hypophyseal portal system all the way to the pituitary gland. The adenohypophysis cells in the pituitary gland are then stimulated by the Gonadotropin-Releasing Hormone to secrete both the Follicle Stimulating Hormone and the Luteinizing Hormone (Johnson, 2012). The secretory cells in the pituitary gland have receptors that accommodate the Gonadotropin-Releasing Hormone from the hypothalamus as it stimulates the pituitary glands to secrete the two reproductive hormones (Dyer, 1989). The Follicle Stimulating Hormone and the Luteinizing Hormone are then released to the bloodstream immediately after being produced to play a critical role in controlling the activities of gonads (Johnson, 2012).
The menstrual cycle is normally regulated by the two hormones from the pituitary glands (Dyer, 1989). The Luteinizing Hormone and the Follicle Stimulating Hormone stimulate the ovaries which are the female gonads to produce two female reproductive hormones which include estrogen and inhibin. The two hormones produced by the ovaries are responsible for regulating the entire menstrual cycle (Johnson, 2012). The Luteinizing Hormone in men stimulates the testicles which are the male gonads to produce a male reproductive hormone known as testosterone. The interstitial cells located within the testis are the ones responsible for secreting testosterone. On the other hand, the Follicle Stimulating Hormone facilitates the production of sperms in men through a process called spermatogenesis (Johnson, 2012). The amount of estrogen in men is very negligible and does not have any effect on the male reproductive system.
The ovarian and uterine cycles are controlled by the hypothalamus effect (Johnson, 2012). The activities of the hypothalamus are normally put in check by the ovary depending on whether conception takes place or not. During ovulation time, a regulatory hormone is known as progesterone is normally released by the ovary to inhibit the reproductive activities of the hypothalamus in case of a conception (Dyer, 1989). If conception does not take place after ovulation, the hypothalamus begins another reproductive cycle. In men, spermatogenesis is normally regulated by testosterone which communicates with the hypothalamus (Johnson, 2012). The inhibin hormone that is normally produced by both male and female gonads is meant to control the production of the Gonadotropin-Releasing Hormone in the hypothalamus (Johnson, 2012). The brain plays a critical role in the entire human reproduction system by controlling all the reproduction cycles.
References
Dyer, R. (1989). Brain opioid systems in reproduction. London: Oxford University Press.
Johnson, M. (2012). Essential reproduction. New York, NY: John Wiley & Sons.