Question

Menstruation is triggered by:

A) Increased production of estrogen by the dominant follicle

B) Degeneration of the corpus luteum and the accompanying decline in circulating progesterone and estrogen levels

C) The LH surge

Answer 1

Menstruation is triggered by the degeneration of the corpus luteum and the accompanying decline in progesterone and estrogen levels, leading to the shedding of the uterine lining.

Step-by-step explanation:

Menstruation is triggered by the degeneration of the corpus luteum and the accompanying decline in circulating progesterone and estrogen levels. This process begins if no fertilized egg is implanted into the uterus. The decrease in these hormones causes the endometrium to degenerate, leading to the shedding of the uterine lining and the start of the menstrual period. The high estrogen levels during the earlier phases of the cycle, before ovulation, lead to a surge in LH (Luteinizing Hormone), which is responsible for triggering ovulation, not menstruation.