Normally menstruation occurs when _ _.
A)blood levels of estrogen and progesterone increase
B)blood levels of FSH fall off
C)blood levels of estrogen and progesterone decrease
D)the corpus luteum secretes estrogen

Question

Quizplus · Accepted Answer

Menstruation occurs when the levels of estrogen and progesterone decrease, causing the uterine lining to shed. The corpus luteum secretes progesterone, which helps maintain the uterine lining, but if an egg is not fertilized, the corpus luteum breaks down, causing a decrease in progesterone levels and triggering menstruation. FSH levels rise at the beginning of the menstrual cycle to stimulate the development of follicles in the ovaries, and blood levels of estrogen and progesterone increase during the menstrual cycle but decrease before menstruation.

Normally Menstruation Occurs When _ _