Which hormone surge triggers ovulation?

Which hormone surge triggers ovulation?

• A. LH
• B. FSH
• C. Estrogen
• D. Progesterone

Answer: (A)

The release of the egg at mid-cycle is driven by a surge of luteinizing hormone. As the dominant follicle matures, it releases increasing amounts of estrogen; this rising estrogen produces a positive feedback effect on the hypothalamus and anterior pituitary, triggering a sharp LH spike. The LH surge then causes the follicle to rupture and ovulation to occur about 24–36 hours later. Follicle-stimulating hormone helps the follicle grow earlier in the cycle, but it is not the main trigger for ovulation. After ovulation, the corpus luteum forms and secretes progesterone to support the endometrium.

The release of the egg at mid-cycle is driven by a surge of luteinizing hormone. As the dominant follicle matures, it releases increasing amounts of estrogen; this rising estrogen produces a positive feedback effect on the hypothalamus and anterior pituitary, triggering a sharp LH spike. The LH surge then causes the follicle to rupture and ovulation to occur about 24–36 hours later. Follicle-stimulating hormone helps the follicle grow earlier in the cycle, but it is not the main trigger for ovulation. After ovulation, the corpus luteum forms and secretes progesterone to support the endometrium.