During menstruation, if the egg released during ovulation is not fertilized by sperm, it is reabsorbed by the body. The uterine lining, which thickened in preparation for a potential pregnancy, sheds, resulting in the menstrual flow.
The Menstrual Cycle and the Egg's Fate
The menstrual cycle is a complex hormonal process. A key event is ovulation, where a mature egg is released from an ovary. This egg travels down the fallopian tube.
- Fertilization: If sperm fertilizes the egg, it implants in the uterine lining, initiating pregnancy.
- No Fertilization: If fertilization doesn't occur, the egg disintegrates and is reabsorbed. Hormone levels (estrogen and progesterone) drop, triggering the shedding of the uterine lining (endometrium). This shedding constitutes the menstrual period or menstrual flow.
The average menstrual cycle lasts about 28 days, but this can vary significantly between individuals. The timing of ovulation within the cycle can also vary. Resources like the NHS website (https://www.nhs.uk/conditions/periods/fertility-in-the-menstrual-cycle/) provide more detail on the menstrual cycle and fertility.
In summary, the egg's fate during menstruation depends entirely on whether fertilization has occurred. If not, it is simply reabsorbed into the body.
