Functional anatomy and physiology of the female breast.

As mammals, we define our biologic class by the function of the breast in nourishing our young. As obstetricians, we seek to enhance or diminish function; as gynecologists, the appearance of inappropriate lactation (galactorrhea) may signify serious disease. In this article, development, differentiation, and functional anatomy of the breast is discussed. The hormonal interactions responsible for these events and the physiologic function of this vital reproductive organ during the life cycle of the woman is emphasized.