Question

Once an oocyte is ‘chosen’, know the steps leading to ovulation

Answer 1

Once an oocyte is selected, the following steps lead to ovulation:

1. The follicle that contains the oocyte starts to grow and mature under the influence of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) produced by the pituitary gland.
2. The oocyte undergoes meiosis I and produces a secondary oocyte and a polar body.
3. As the follicle continues to grow, it fills with fluid, and the pressure inside increases.
4. At a certain point, usually around day 14 of a 28-day menstrual cycle, the follicle ruptures and releases the mature oocyte from the ovary. This process is known as ovulation.
5. The released oocyte is swept up by the fimbriae of the fallopian tube and begins its journey towards the uterus.
6. If the oocyte is fertilized by a sperm during its journey, it may implant in the uterine lining and develop into a fetus. If the oocyte is not fertilized, it will degenerate and be expelled from the body during menstruation.