Gonadotrofinsyklusen

Gonadotrofinsyklusen refers to the cyclical release of gonadotropins, primarily follicle-stimulating hormone (FSH) and luteinizing hormone (LH), from the anterior pituitary gland. These hormones play a crucial role in the reproductive system of both males and females, although the cyclical nature is most pronounced in females.

In females, the gonadotrofinsyklusen is intimately linked to the menstrual cycle. During the follicular phase, FSH stimulates the growth and maturation of ovarian follicles. As follicles develop, they produce estrogen, which in turn exerts feedback effects on the pituitary. A surge in LH, triggered by rising estrogen levels, leads to ovulation, the release of a mature egg from the ovary. Following ovulation, the corpus luteum forms and secretes progesterone and estrogen. These hormones prepare the uterus for potential pregnancy and also influence further gonadotropin release. If fertilization does not occur, the corpus luteum degenerates, leading to a drop in hormone levels and the start of menstruation, after which the cycle begins anew.

In males, the gonadotrofinsyklusen is less distinctly cyclical but still involves the pulsatile release of FSH and LH. FSH stimulates spermatogenesis, the production of sperm in the testes. LH stimulates the Leydig cells in the testes to produce testosterone, which is essential for male sexual development and the maintenance of reproductive function. While not characterized by monthly fluctuations like in females, the secretion of these hormones in males is regulated by feedback mechanisms involving testosterone and other hormones.