The answer is the pituitary gland secretes follicle stimulating hormone, which acts on the follicles and stimulates them to produce progesterone.
The endometrial lining is where the fertilized egg implants, or burrows and attaches itself to the uterine wall, where it will continue to grow and be nourished. There are three layers of the uterus: The perimetrium is the outer layer, the myometrium is in the middle, and the endometrium is the inner layer of the uterine wall.
