hipotalamuszhipofízisovarialis

The hypothalamic-pituitary-ovarian (HPO) axis is a complex endocrine system that regulates reproductive function in females. It involves a tightly coordinated interplay between the hypothalamus, the pituitary gland, and the ovaries. The hypothalamus, located in the brain, releases gonadotropin-releasing hormone (GnRH) in a pulsatile manner. This GnRH then acts on the anterior pituitary gland, stimulating it to release two key hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

FSH and LH are collectively known as gonadotropins. They travel through the bloodstream to the ovaries. In the ovaries, FSH stimulates the growth and development of ovarian follicles, which contain the eggs. As follicles mature, they produce estrogen, a primary female sex hormone. Estrogen plays a crucial role in the development of secondary sexual characteristics and prepares the uterus for potential pregnancy.

LH, on the other hand, triggers ovulation, the release of a mature egg from the dominant follicle. Following ovulation, the ruptured follicle develops into the corpus luteum, which produces progesterone. Progesterone is essential for maintaining the uterine lining and supporting a potential pregnancy. The levels of estrogen and progesterone also exert feedback control on the hypothalamus and pituitary gland, regulating the release of GnRH, FSH, and LH. This intricate feedback loop ensures that the reproductive cycle proceeds in a regulated and timely manner. Disruptions in any part of the HPO axis can lead to various reproductive health issues.