Menstruation is initiated by
A) a rapid increase in estrogen levels.
B) a rapid drop in estrogen levels.
C) a rapid drop in progesterone levels.
D) both (a) and (b) above.
E) both (b) and (c) above.

Question

Quizplus · Accepted Answer

Menstruation is initiated by a rapid drop in progesterone levels, which causes the shedding of the uterine lining. This drop in progesterone is typically caused by the abrupt decline in estrogen levels that occurs at the end of the menstrual cycle. Therefore, both (b) and (c) above are correct.

Menstruation Is Initiated by