Which hormone is secreted by the pituitary gland to promote ovulation?

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

Answer: (A)

Ovulation is triggered by a surge of luteinizing hormone from the anterior pituitary. In the ovarian cycle, signals from the hypothalamus cause the pituitary to release both FSH and LH. FSH helps follicles mature, while rising estrogen from the maturing follicle eventually prompts a sharp LH surge. This LH spike causes the dominant follicle to rupture and release the egg. LH also stimulates the corpus luteum after ovulation to produce progesterone, which prepares the uterus for possible implantation. The other hormones listed—estrogen and progesterone—are ovarian steroids, not pituitary hormones that initiate ovulation, and FSH drives follicle growth but does not itself trigger ovulation.