[Campbell Biology P.1081] Which of the following accurately describes the regulation of GnRH ... | Practice Question

Which of the following accurately describes the regulation of GnRH secretion by the hypothalamus during the human female reproductive cycle, as depicted in Figure 46.14?

  • option_A: High levels of estradiol stimulate GnRH secretion, leading to the LH surge.
  • option_B: GnRH secretion is continuously inhibited by FSH and LH throughout the cycle.
  • option_C: Low levels of progesterone stimulate GnRH secretion.
  • option_D: A combination of estradiol and progesterone consistently stimulates GnRH secretion.

Explanation

Figure 46.14 illustrates both positive and negative feedback on GnRH. On 'DAY 14', high levels of estradiol are shown to positively stimulate the hypothalamus, leading to increased GnRH release and subsequently the LH surge. In contrast, during 'DAYS 15-28', a combination of estradiol and progesterone inhibits GnRH secretion, representing negative feedback.