Hormonal control
The regulation of the female reproductive system is controlled by a series of hormones that work in coordination to ensure proper development, ovulation, and pregnancy maintenance. The major hormones involved are Gonadotropin-releasing hormone (GnRH), Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), Estrogen, and Progesterone.
1. Role of the Hypothalamus
The hypothalamus releases Gonadotropin-releasing hormone (GnRH). GnRH stimulates the anterior pituitary gland to secrete two key gonadotropins: Follicle-stimulating hormone (FSH) Luteinizing hormone (LH)
2. Role of the Pituitary Gland
FSH (Follicle-stimulating hormone) Stimulates the growth and development of ovarian follicles. Initiates the maturation of oocytes (eggs) within the follicles. Triggers the follicles to produce estrogen. LH (Luteinizing hormone) Stimulates the maturation of the dominant follicle. Triggers ovulation, which is the release of a mature oocyte from the ovary. Stimulates the formation of the corpus luteum from the ruptured follicle. Stimulates the corpus luteum to produce progesterone.
3. Role of the Ovaries
The ovaries respond to FSH and LH by producing two key hormones: Estrogen Progesterone
Functions of Estrogen: Secreted by growing ovarian follicles. Responsible for the development of female secondary sexual characteristics such as: Growth of breasts. Development of pubic and body hair. Widening of the pelvis. Fat deposition in the hips, thighs, and buttocks. Stimulates the proliferation of the endometrium (uterine lining) for possible implantation of an embryo.
Functions of Progesterone:
Secreted by the corpus luteum after ovulation. Prepares and maintains the uterine lining (endometrium) for pregnancy. Inhibits GnRH release, thus preventing further ovulation. Helps in the maintenance of pregnancy.
4. Feedback Mechanism in Hormonal Regulation
Positive Feedback: High levels of estrogen from the growing follicles stimulate the anterior pituitary to release LH surge, leading to ovulation.
Negative Feedback: Rising levels of progesterone from the corpus luteum inhibit the release of GnRH, which suppresses the secretion of FSH and LH. This prevents the development of new follicles while the body prepares for pregnancy.