Breast tissue Light micrograph of a section through tissue from the human mammary gland during pregnancy The breast is normally made up of fibrofatty connective tissue which surrounds the small lactiferous milkforming glands and ducts leading to the nipple This sample shows that during pregnancy the breast mainly consists of lactiferous glands and ducts and acini masses of secretory cells which have proliferated and the original adipose fat tissue is greatly reduced Magnification x when printed at centimetres across