Milk glands are also commonly referred to as mammary glands. They are the key components of the female mammalian reproductive system and are responsible for the production and secretion of milk. Other synonyms for milk gland include lactiferous gland, udder, and breast. Lactiferous gland is a term typically used in the scientific community and refers specifically to the glands that produce milk. Udder is a term typically used to describe the milk gland of cows, sheep, and other livestock. Breast is a term commonly used to refer to the milk glands of humans and refers to the anatomical structure that encompasses the lactiferous glands.