Which hormone surge triggers ovulation?

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

Answer: (C)

The hormone responsible for triggering ovulation is luteinizing hormone (LH). During the menstrual cycle, a surge in LH is a critical event that occurs typically around the middle of the cycle, following a rise in estrogen levels. This surge is essential for the final maturation of the ovarian follicle and the subsequent release of the egg from the ovary.

As ovulation approaches, the levels of estrogen increase due to the developing follicle, which then stimulates a dramatic rise in LH. This LH surge causes the follicle to rupture, leading to the release of the egg into the fallopian tube, a process known as ovulation.

Other hormones, such as progesterone and follicle-stimulating hormone (FSH), play important roles in the menstrual cycle and reproductive process, but they do not directly trigger ovulation in the way that LH does. Progesterone is primarily involved in preparing the uterine lining for potential implantation after ovulation, while FSH is critical for the initial growth and maturation of ovarian follicles. Estrogen, while important in regulating the cycle and facilitating the LH surge, does not by itself induce ovulation. Therefore, the LH surge is the definitive trigger for the ovulation process.