Which hormone is primarily responsible for triggering ovulation?

Which hormone is primarily responsible for triggering ovulation?

• A. Luteinizing hormone
• B. Follicle-stimulating hormone
• C. Estrogen
• D. Progesterone

Answer: (A)

Ovulation is initiated by a surge of luteinizing hormone. As a dominant follicle matures, rising estrogen levels create a brief positive feedback signal to the pituitary, driving a sharp LH release around the mid-cycle. This LH surge triggers the rupture of the follicle and release of the oocyte, and it also helps form the corpus luteum afterward. Follicle-stimulating hormone mainly supports follicle growth earlier in the cycle, not the actual ovulation event. Estrogen rises as the follicle matures and contributes to the LH surge and endometrial preparation, but it is the LH spike that directly triggers ovulation. Progesterone comes into play after ovulation to support the endometrium, not to trigger ovulation.

Ovulation is initiated by a surge of luteinizing hormone. As a dominant follicle matures, rising estrogen levels create a brief positive feedback signal to the pituitary, driving a sharp LH release around the mid-cycle. This LH surge triggers the rupture of the follicle and release of the oocyte, and it also helps form the corpus luteum afterward. Follicle-stimulating hormone mainly supports follicle growth earlier in the cycle, not the actual ovulation event. Estrogen rises as the follicle matures and contributes to the LH surge and endometrial preparation, but it is the LH spike that directly triggers ovulation. Progesterone comes into play after ovulation to support the endometrium, not to trigger ovulation.