When do mammary glands produce milk

Anatomy of the Female Breast The nipple and areola the dark area around the nipple enlarge and darken during pregnancy. Oxytocin causes the cells around the alveoli to contract and eject your milk down the milk ducts. Let-down is experienced in numerous ways including: Your infant begins to actively suck and swallow. Milk may drip from the opposite breast.

You may feel a tingling or a full sensation after the first week of nursing in your breasts or uterine cramping. You may feel thirsty. Interference With Let-Down A variety of factors may interfere with let-down: Emotions such as embarrassment, anger, irritation, fear or resentment Fatigue Poor suckling from improper positioning Not enough time baby is actively nursing Stress Negative remarks from relatives or friends Pain in your breasts or uterus i.

Before beginning the feeding, unplug the phone, turn on relaxing music and do deep breathing. Take four or five deep abdominal breaths. Interact with friends and breastfeeding professionals who are supportive of breastfeeding. Do not let well-meaning friends and relatives who have different attitudes discourage you.

Restrict visitors until you are comfortable. Be around other nursing mothers. Be sure your baby is positioned properly and allow enough suckling time. Your Milk Colostrum Colustrom, the early milk made by your breasts, is present in small amounts for the first three days to match the small size of your baby's stomach. Foremilk — When first starting to breastfeed, the first milk the baby receives is called foremilk. It is thin and watery with a light blue tinge.

Hind-milk — Hind-milk is released after several minutes of nursing. It is similar in texture to cream and has the highest concentration of fat. The hind-milk has a relaxing effect on your baby. Hind-milk helps your baby feel satisfied and gain weight.

The Family's Role The family plays a major role in the breastfeeding relationship between you and your baby. Related Articles. More Resources. Medical Library Look up helpful health information. Diseases and Conditions See our full library of diseases and conditions.

Patient Information Practical info for Sutter patients. Tools and Quizzes Online tools to help you make decisions about your health. The Sutter Health Network of Care. Expertise to fit your needs. Primary Care. Check-ups, screenings and sick visits for adults and children. The process occurs in all female mammals, although it predates the origin of mammals. In humans the process of feeding milk is called breastfeeding or nursing.

The chief function of lactation is to provide nutrition and immune protection to the young after birth. In almost all mammals, lactation induces a period of infertility, which serves to provide the optimal birth spacing for survival of the offspring.

In only one species of mammal, the dayak fruit bat, is milk production a normal male function. In some other mammals, the male may produce milk as the result of a hormone imbalance. Galactopoiesis is the maintenance of milk production.

This stage requires prolactin and oxytocin. By the fifth or sixth month of pregnancy, the breasts are ready to produce milk. This is when the breasts make colostrum, a thick, sometimes yellowish fluid. Milk drains from lactiferous ducts into lactiferous sinuses that meet at 4 to 18 perforations in the nipple, called nipple pores.

The small bumps of the areola the darkened skin around the nipple are called Montgomery glands. They secrete oil to cleanse the nipple opening and prevent chapping and cracking of the nipple during breastfeeding.

The pituitary hormone prolactin is instrumental in the establishment and maintenance of breast milk supply. It also is important for the mobilization of maternal micronutrients for breast milk.

Near the fifth week of pregnancy, the level of circulating prolactin begins to increase, eventually rising to approximately 10—20 times the pre-pregnancy concentration. We noted earlier that, during pregnancy, prolactin and other hormones prepare the breasts anatomically for the secretion of milk.

The level of prolactin plateaus in late pregnancy, at a level high enough to initiate milk production. However, estrogen, progesterone, and other placental hormones inhibit prolactin-mediated milk synthesis during pregnancy.

It is not until the placenta is expelled that this inhibition is lifted and milk production commences. After childbirth, the baseline prolactin level drops sharply, but it is restored for a 1-hour spike during each feeding to stimulate the production of milk for the next feeding. With each prolactin spike, estrogen and progesterone also increase slightly. When the infant suckles, sensory nerve fibers in the areola trigger a neuroendocrine reflex that results in milk secretion from lactocytes into the alveoli.

The posterior pituitary releases oxytocin, which stimulates myoepithelial cells to squeeze milk from the alveoli so it can drain into the lactiferous ducts, collect in the lactiferous sinuses, and discharge through the nipple pores. It takes less than 1 minute from the time when an infant begins suckling the latent period until milk is secreted the let-down. The image below summarizes the positive feedback loop of the let-down reflex. Figure 1. Click for a larger image. A positive feedback loop ensures continued milk production as long as the infant continues to breastfeed.

Just before the nipple, the lactiferous duct enlarges to form a lactiferous sinus ampulla , which serves as a reservoir for milk. After the sinus, the duct again narrows and each duct opens independently on the surface of the nipple. Mammary gland function is regulated by hormones. At puberty , increasing levels of estrogen stimulate the development of glandular tissue in the female breast.