When the corpus luteum degenerates

A. Circulating levels of estrogen and progesterone rapidly decline.

B. FSH and LH secretion start to rise as the inhibitory effects of the gonadal steroids are withdrawn.

C. The endometrium sloughs off.

D. Both A and B are correct.

E. All of the preceding are correct.

E. All of the preceding are correct

Explanation:

When the corpus luteum stops secreting progesterone and estrogen, the

Concentration of these hormones in the blood drops.

As a result, small arteries in the endometrium contract, reducing

the oxygen supply. Menstruation, which marks the beginning

of a new cycle, begins when cells die (due to the lack of oxygen) and blood vessels break and bleed. Estrogen concentrations and

Progesterone are now too low to inhibit the anterior pituitary,

so the secretion of HSF and HL grows again.