Final answer:
The instructor would discuss the follicular, ovulation, and luteal phases of the ovarian cycle, explaining the hormonal changes and the maturation of follicles leading to ovulation and the subsequent formation of the corpus luteum.
Step-by-step explanation:
When teaching about the ovarian cycle, there are three main phases that the instructor would need to include in the lesson. The follicular phase is the initial phase, where several ovarian follicles begin to mature due to an increase in follicle-stimulating hormone (FSH). Typically this phase lasts for about 12 to 14 days, leading up to ovulation. Ovulation occurs around day 14, triggered by a surge in estrogen and luteinizing hormone (LH), resulting in the release of an egg from the dominant follicle. Following ovulation is the luteal phase, during which the ruptured follicle transforms into the corpus luteum that secretes progesterone. This phase also roughly spans two weeks if fertilization does not occur, leading to the degeneration of the corpus luteum. These stages are crucial in understanding the reproductive cycle and fertility. In the follicular phase, estrogen levels rise, promoting the maturation of one dominant Graafian follicle. The ovulation marks the midpoint of the ovarian cycle, while the luteal phase prepares the body for possible implantation of a fertilized egg. If the LH surge does not happen, ovulation is prevented and the egg remains within the follicle, which could potentially lead to an anovulatory cycle.