Final answer:
FSH stimulates the growth and maturation of ovarian follicles and the production of estrogen, which prepares the uterine lining for potential pregnancy. It works alongside LH but is not directly responsible for triggering ovulation or producing progesterone during the luteal phase.
Step-by-step explanation:
FSH, or follicle-stimulating hormone, plays a pivotal role in the regulation of the female reproductive system. At the beginning of the menstrual cycle during the follicular phase, FSH is responsible for stimulating the growth and maturation of ovarian follicles. Each follicle contains an egg (ova) and is surrounded by cells that help the egg to develop. As the follicle grows, these cells start to produce estradiol, a type of estrogen, which leads to the build-up of the uterine lining, preparing it for potential pregnancy.
FSH does not directly trigger ovulation; that role is primarily taken by luteinizing hormone (LH). However, FSH alongside LH stimulates the maturation of the dominant follicle. At ovulation, usually on day 14 of the cycle, the mature follicle releases the egg due to an LH surge. Post ovulation, during the luteal phase, the remnants of the follicle transform into the corpus luteum, which produces progesterone, necessary to maintain the uterine lining for potential implantation. If the egg is not fertilized, the corpus luteum degenerates, leading to a drop in progesterone and estrogen levels, which subsequently triggers menstruation. Throughout this cycle, inhibin is also produced, which decreases FSH levels to prevent the maturation of more follicles during that time.