The breast is part of the body’s intricate system of reproduction. Although called a mammary gland, the breast is actually an organ. Each breast is an individual exocrine gland that functions and develops independently to extract material from the blood and convert it into milk.
The nipple extends and becomes firmer when stimulated, enabling the baby to latch onto the breast for nursing. The nipple is flexible and able to mold to conform to the baby’s mouth during feeding. Sensory nerve endings in the nipple trigger milk release when the baby suckles. Each nipple has 15 to 20 openings for milk to flow. Ductule openings, commonly called nipple pores, are located at the end of the nipple and enable the baby to receive the milk. Washing the nipples with any substance other than plain water may remove this natural lubrication, dry out the breast skin, and reduce the scent. It is not usually necessary to use creams or oils on the nipples, and use of these items may reduce the amount of air reaching the tissue. Creams may also introduce a scent or taste that the baby dislikes or does not recognize.
The areola is the dark circular area surrounding the nipple. Its size and color vary greatly from woman to woman. During puberty, menstruation, and pregnancy, the areola enlarges and becomes darker in color. There is little subcutaneous fat under the areola, and the underlying ducts are superficial and easily compressed.
To nurse effectively, the baby’s mouth needs to enclose a sizable portion of the areolar tissue. This enables the infant’s tongue to compress a large amount of breast tissue against the palate to facilitate milk release. Many mothers will have heard that they need to get the entire areola into the baby’s mouth. This is incorrect for mothers with, especially large areolae. Instead, the baby should take in an area of areolar tissue that is approximately 1 inch in diameter.
The small bumps on the areola that look sort of like pimples are called Montgomery glands. They produce a natural oil that cleans, lubricates, and protects the nipple during pregnancy and breastfeeding. This oil contains an enzyme that kills bacteria and makes breast creams unnecessary.Because of this natural lubrication, the nipple and areola do not require creams and lotions to keep them soft and healthy. Montgomery gland secretions allow the skin to breathe and remain pliable. Some say that these secretions provide a taste and smell that enable the baby to find the nipple.
Nerves provide a triggering mechanism for milk synthesis and release. The blood and lymph systems bring nourishment to breast tissue, supply the nutrients for milk, and filter out bacteria and cast-off dead cell parts.
The amount of fatty and glandular tissue present determines breast size, but these tissues do not contribute to milk synthesis or transport. The amount of fat or size of the breast is little indication of the quality or quantity of milk the mother will produce. Women with large or small breasts are equally capable of producing milk. Women with larger breasts may be more likely to have a larger storage capacity, explaining why some women deliver larger feedings to their infants at one time than other women.
The production of milk takes place in the breast in tiny individual glands called alveoli. Alveoli consist of epithelial cells encased in a dense basket like meshwork of smooth muscle, known as myoepithelial cells. Numerous capillaries surround the alveoli and bring nutrient-rich blood from which the alveoli make milk. Through this same system, the alveoli receive the hormones oxytocin and prolactin, which signal them to release and produce more milk.
Sources:
Counseling the Nursing Mother: A Lactation Consultant’s Guide, Fifth Edition