the potential and active compound, alveolar, mostly merocrine (with possible apocrine components) milk-secreting gland lying within the breast; it comprises 15-24 lobes, each consisting of many lobules, separated by adipose tissue and fibrous septa; the parenchyma of the resting postpubertal female gland consists of ducts; the alveoli develop only during pregnancy and remain active until weaning; normally, the gland remains rudimentary (undistinguishable from its childhood state) in men.
See also:
breast (2).