Which statement correctly identifies what triggers ovulation?

Which statement correctly identifies what triggers ovulation?

• A. Luteinizing hormone (LH) surge triggers ovulation
• B. Follicle-stimulating hormone (FSH) surge triggers ovulation
• C. Estrogen decline triggers ovulation
• D. Progesterone surge triggers ovulation

Answer: (A)

The key event that triggers ovulation is a surge of luteinizing hormone from the anterior pituitary. This LH surge is brought about when rising estrogen levels from the maturing follicle signal the hypothalamus and pituitary to release a large amount of LH. The sudden LH rise acts on the follicle to weaken and rupture its wall, releasing the oocyte—this is ovulation. While FSH helps with follicle growth and estrogen production, it is the LH surge that directly initiates the ovulatory event. After ovulation, progesterone rises from the corpus luteum to support the uterus; an estrogen decline or a progesterone surge before ovulation does not trigger the release of the oocyte.

The key event that triggers ovulation is a surge of luteinizing hormone from the anterior pituitary. This LH surge is brought about when rising estrogen levels from the maturing follicle signal the hypothalamus and pituitary to release a large amount of LH. The sudden LH rise acts on the follicle to weaken and rupture its wall, releasing the oocyte—this is ovulation. While FSH helps with follicle growth and estrogen production, it is the LH surge that directly initiates the ovulatory event. After ovulation, progesterone rises from the corpus luteum to support the uterus; an estrogen decline or a progesterone surge before ovulation does not trigger the release of the oocyte.