How is the mammary gland designed?

The mammary gland is a milk-producing structure that is composed largely of fat cells (cells capable of storing fat). The fat deposits are laid down in the breast under the influence of the female hormone estrogen. Just as the surge of estrogens at adolescence encourages this process, androgens, such as testosterone, discourage it.

Within the mammary gland there is a complex network of branching ducts (tubes or channels). These ducts exit from sac-like structures called lobules.

The lobules in the breast are the glands that can produce milk in females when they receive the appropriate hormonal stimulation.

The breast ducts transport milk from the lobules out to the nipple. The ducts exit from the breast at the nipple.

Picture of the anatomy of the breast