This system has several complex hormonal and anatomical functions. One of them is controlling the cycle of getting the uterus ready to house a baby and coordinates making an egg available at the same time as the uterus is ready to nurture it. Another set of functions deals with the physical plumbing and wiring for sexual activity and fertilization and pregnancy. A third deals with nurturing the baby with nutritious and immune system boosting milk after it’s born. Its a miracle it all works and it is even more impressive when you understand more about it.