During which phase of menstruation does the shedding of the endometrium occur?

• A. Ovulatory
• B. Follicular
• C. Luteal
• D. Endometrial

Answer: (B)

The shedding of the endometrium occurs during the menstrual phase, which is most commonly associated with the follicular phase of the next cycle. After ovulation, in the luteal phase, if pregnancy does not occur, hormonal changes lead to the breakdown of the endometrium, resulting in menstruation. This process is initiated when estrogen and progesterone levels drop toward the end of the luteal phase. The follicular phase refers to the time when the follicles are developing in the ovaries and the endometrium is being rebuilt in response to rising estrogen levels after menstruation has taken place.

The shedding occurs as a result of the complex interplay of hormones, predominantly the withdrawal of progesterone, which triggers the endometrial cells to undergo apoptosis (programmed cell death) and the sloughing off of the tissue occurs, leading to menstruation. Thus, the correct context for the shedding of the endometrium relates to the changes that complete the menstrual cycle.