Which statement is NOT a function of progesterone and estrogen in the menstrual cycle?

• A. Inhibits the production of LH and FSH
• B. Maintains the endometrium for pregnancy
• C. Stimulates ovulation
• D. Provides feedback to the hypothalamus to regulate GnRH

Answer: (C)

Understanding how estrogen and progesterone shape the menstrual cycle hinges on how these hormones provide feedback to the hypothalamus and pituitary, and how they prepare and maintain the uterus for potential pregnancy. Estrogen drives the proliferative growth of the endometrium and, when its level rises high enough near mid-cycle, it creates a brief positive feedback to the hypothalamus and pituitary that triggers the luteinizing hormone (LH) surge. That LH surge is the actual event that leads to ovulation, not a direct action of estrogen or progesterone themselves stimulating ovulation. Progesterone, after ovulation, shifts roles to support and maintain a secretory endometrium, making the lining suitable for implantation and early pregnancy. Both hormones routinely contribute to feedback that modulates GnRH release and the broader regulation of LH and FSH.

So the statement that is not a function of progesterone and estrogen in the cycle is stimulation of ovulation, since the hormones set up the conditions and trigger LH release, but the direct ovulation event is driven by the LH surge rather than these hormones acting alone.