Which hormone surge triggers ovulation?

• A. Follicle Stimulating Hormone (FSH)
• B. Estradiol
• C. Luteinizing Hormone (LH)
• D. Progesterone

Answer: (C)

The surge of Luteinizing Hormone (LH) is the critical event that triggers ovulation. During the menstrual cycle, the increasing levels of estradiol, produced by the developing follicles, lead to a peak in LH levels just before ovulation. This surge causes the mature follicle to release an egg from the ovary.

LH is essential for the final maturation of the ovarian follicle and the subsequent release of the ovum. After ovulation, LH also plays a role in transforming the ruptured follicle into the corpus luteum, which produces progesterone to support any potential pregnancy. While Follicle Stimulating Hormone (FSH) is vital for the initial development of ovarian follicles, estradiol is important for regulating the menstrual cycle and preparing the endometrium for implantation, it is the LH surge that directly induces the release of the egg, marking the ovulation phase. Progesterone, while essential for maintaining a pregnancy, is produced after ovulation has occurred, not as a trigger for the process itself.