After ovulation, the ruptured Graafian follicle transforms into a corpus luteum which mainly secretes

After ovulation, the ruptured Graafian follicle transforms into a corpus luteum, which secretes mainly progesterone. Progesterone prepares and maintains the endometrium for implantation of a fertilized ovum. Progesterone also acts on the mammary glands and stimulates the formation of alveoli and milk secretion.