Mammary glands are milk-producing glands which are functional in nursing offspring. “Mammary” came from the Latin word “mamma” which translates to “breast." Normally, humans have two complex mammary glands where lactation occurs. These glands are regulated by the endocrine system. The major parts of the mammary glands include the milk glands, nipple, connective tissue, lactiferous ducts, and areola.