Menstruation is triggered by
A) reduced secretion of estrogen and progesterone from the corpus luteum.
B) implantation of a fertilized ovum in the uterus.
C) androgens from the adrenal cortex.
D) estrogens from the adrenal cortex.
E) increased secretion of estrogen and progesterone from the corpus luteum.

Question

Quizplus · Accepted Answer

Menstruation occurs when the lining of the uterus sheds, which is triggered by a drop in estrogen and progesterone levels. The corpus luteum, which develops from the empty follicle after an ovum is released, secretes these hormones. If fertilization and implantation occur, the developing embryo releases a hormone called human chorionic gonadotropin (hCG) which maintains the corpus luteum, preventing it from degenerating and continuing to secrete estrogen and progesterone. If implantation does not occur, the corpus luteum degenerates and hormone levels drop, leading to menstruation. Therefore, option A is the correct answer.

Menstruation Is Triggered by