The concept establishes the cyclic regulation of the female reproductive axis through the oscillatory interaction between the hypothalamic-pituitary-gonadal (HPG) axis and ovarian follicular dynamics. This abstract theory defines the periodic alternation of four distinct physiological phases—menstrual, follicular, ovulatory, and luteal—governed by specific thresholds of gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen, and progesterone. It serves as the formal biomechanical model describing how endocrine feedback loops dictate the temporal architecture of gametogenesis and endometrial remodeling within human physiology.
The female reproductive cycle is governed by a hypothalamic-pituitary-gonadal feedback loop: GnRH from the hypothalamus stimulates anterior pituitary release of FSH and LH, which drive follicular dev…