BREAST,ILLUSTRATION. ´BREAST,ILLUSTRATION The breast, or mammary gland, has the nipple in its center. The nipple is surrounded by a pigmented area known as the areola. The mammary gland is composed of lobes located within fatty tissue. These lobes contain the lactiferous ducts that lead out to and through the nipple.The breasts rest on the pectoral muscle. They are held up by the skin and the fibrous structures of the mammary gland. The biological function of the breast is to produce milk.´