Pituitary and ovary. The pituitary hormones FSH and LH help the egg sac, or follicle grow and mature. A sudden surge of LH induces ovulation. The ovary produces estradiol, to prepare the pelvic organs and progesterone, after ovulation, to stabilize the endometrial lining for pregnancy.
LH and progesterone. Estrogen levels are detected by the brain which then releases something call leutinizing hormone (lh) which induces ovulation. After ovulation, Progesterone levels increase.