hypothalamushypophysisgonadális

The hypothalamic-hypophyseal-gonadal axis, often abbreviated as the HPG axis, is a complex neuroendocrine system that regulates reproduction and sexual development in vertebrates. This intricate feedback loop involves the hypothalamus, the pituitary gland (hypophysis), and the gonads (testes in males and ovaries in females). The hypothalamus, located in the brain, produces gonadotropin-releasing hormone (GnRH). GnRH then travels to the anterior pituitary gland, stimulating it to release two crucial hormones: luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH and FSH are collectively known as gonadotropins. These gonadotropins travel through the bloodstream to the gonads. In the testes, LH stimulates Leydig cells to produce testosterone, while FSH promotes sperm production. In the ovaries, LH triggers ovulation and the formation of the corpus luteum, which produces progesterone, and FSH stimulates the development of ovarian follicles, which produce estrogen. The hormones produced by the gonads, estrogen and testosterone, then exert feedback control on both the hypothalamus and the pituitary gland, either inhibiting or stimulating the release of GnRH, LH, and FSH. This feedback mechanism ensures that hormone levels are maintained within appropriate ranges for normal reproductive function and development. Disruptions in the HPG axis can lead to various reproductive disorders, including infertility and hormonal imbalances.