Lactiferous

Lactiferous is an anatomical adjective used to describe structures that carry or secrete milk. It derives from the Latin lactifer, meaning milk-bearing. In humans, the term is most often applied to the lactiferous ducts of the mammary gland.

Mammary glands consist of lobes and lobules that produce milk. Each lobe drains through lactiferous ducts; these ducts converge toward the nipple and typically open on its surface via multiple openings. Before reaching the nipple, ducts may dilate to form the lactiferous sinus (also called the subareolar or lactiferous sinus), a small reservoir near the areola that stores milk during nursing.

The primary function is the transport of milk from the glandular tissue to the nipple for lactation. The lactiferous system can be involved in conditions such as mastitis during lactation, intraductal papilloma (a growth within a duct), and duct ectasia (dilation of ducts) in older women. Breast imaging and surgery may reference lactiferous ducts when assessing pathology.

In other mammals, the term similarly describes ducts carrying milk from mammary glands, reflecting a common anatomical concept across species.