Lactation

Lactation

Lactation is the process of secreting milk by a mother from their mammary glands, once after giving birth to their young ones is termed as lactation. This mammary gland is located within the fatty tissue of the breasts in all females.

Lactation process

  1. Due to the impact of ovarian hormones and placental hormones, breast growth begins during the period of pregnancy and it continues to get larger in size after the childbirth.
  2. During this period, a certain amount of milk is produced in the breast.
  3. The milk secretion increases only after the baby’s birth.
  4. During the process of lactation, the secreted milk from mammary glands is drained out through the openings found in the nipple.

Hormones that promote lactation

  • Usually hormones like estrogen, placental lactogenic, progesterone, prolactin and oxytocin are involved in the process of lactation.
  • Estrogen hormone helps in increasing the size of the breast during pregnancy causing the growth of breast tissue.
  • The presence of a placental lactogenic hormone is higher during pregnancy as this hormone helps in stimulating the growth of the nipple, areola and breast tissue.
  • Progesterone hormone helps in increasing the size of the breast tissue along with boosting milk production. During post pregnancy period, the progesterone hormone level tends to decrease, which stimulates the milk production.
  • Prolactin hormone helps in differentiating the cells that perform their own specific functions. The alveoli, which is responsible for producing milk after the baby’s birth is active mainly because of prolactin hormone. The prolactin hormone is produced once exposed to cortisol hormone.
  • Once the nipples are stimulated, the oxytocin hormone is released causing the alveoli to contract. These help in squeezing the milk out into the duct system. The entire process is called as a letdown. The let down process begins only when the nerves of breasts are stimulated.

Can lactation happen without pregnancy?

There are three hormones which play an important role in stimulating the milk production in mammary glands of a lactating mother. By consuming medicines of these three hormones in the form of supplements would help women to produce breast milk in their mammary glands without pregnancy.

There are certain other natural tendencies were lactation happens without pregnancy. These include:

  1. Imbalance of hormone.
  2. Side effects from drugs/medicines.
  3. Health disorders.
  4. Nerve irritation in the breast region.
  5. Overproduction of prolactin hormone in the brain.

Properties of milk

  1. The milk produced in an initial stage of lactation varies from the milk after maturation viz. produced when lactation is well established.
  2. The early milk produced in the initial stage of lactation is known as colostrum.
  3. The composition of milk changes gradually after childbirth. The colostrum changes to transitional milk within four-five days from the childbirth.
  4. After 14 to 15 days of childbirth,  matured milk is produced in mammary glands.

The termination of lactation slowly stops with the reduced demand from the baby.

Comparison between the elements of colostrum, transitional and mature milk with cow’s milk (average value per 100ml whole milk)

  Colostrum    (1-5days) Transitional (6-14 days) Mature (after14days) Cow’s milk
Energy, kcal* 58 74 71 69
Total solids, g 12.8 13.6 12.4 12.7
Fat, g 2.9 3.6 3.8 3.7
Lactose, g 5.3 6.6 7.0 4.8
Protein, g 2.7 1.6 1.2 3.3
Casein, g 1.2 0.7 0.4 2.8
Ash, g 0.33 0.24 0.21 0.72
Minerals
Calcium, mg 31 34 33 125
Magnesium, mg 4 4 4 12
Potassium, mg 74 64 55 138
Sodium, mg 48 29 15 58
Iron, mg 0.09 0.04 0.15 0.10

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Practise This Question

Which of the following hormone is secreted by Adrenal Glands?