For the first two days following delivery, no further anatomic changes in the breasts occur. The secretion from the breast called colostrum which starts during pregnancy becomes more abundant.
Percentage composition of colostrum and breast milk
Advantages -
- The antibodies provides immunological defence to new born.
- It has laxative action on the baby because of large fat globules.
Physiology of lactation -
Although lactation starts following delivery, the preparation for effective lactation starts during pregnancy. The physiological basis of lactation is divided into four phages:
a) Preparation of breast (Mammogenesis).
b) Synthesis and secretion from the breast alveoli (Lactogenesis).
c) Ejection of milk (Galactokinesis).
d) Maintenance of lactation (Galactopoiesis).
Mammogenesis -
Pregnancy is associated with a remarkable growth of both the ductal and lobulo-alveolar systems. An intact nerve supply is not essential for the growth of the mammary gland during pregnancy.
Lactogenesis -
Milk secretion actually starts on 3rd or 4th day after delivery. Around this time, the breasts become engorged, tense, tender and feel warm. Inspite of a high prolactine level during pregnancy, milk secretion is kept in abeyance. Probably, the steroids estrogen and progesterone circulating during pregnancy make the breast tissue unresponsive to prolactin. When the estrogen and progesterone are withdrawn following delivery, prolactin begins its milk secretory activity in previously fully developed mammary glands.
Galactogenesis -
Discharge of milk from the mammary glands depends not only on the suction exerted by the baby during suckling but also on the contractile mechanism which expresses the milk from the alveoli into the ducts.
During suckling, a conditioned reflex is set up. The ascending tackle impulses from the nipple and areola pass via hypothalamus to synthesize and transport oxytocin to the posterior pituitary. Oxytocin produces contraction of the myopithelial cells of the alveoli and the ducts containing the milk. This is the 'milk ejection' or 'milk let down' reflex the milk is forced down into the ampulla of the lactiferous ducts, wherefrom it can be expressed by the mother or sucked out by the baby.
Galactopoiesis -
Prolactin appears to be the single most important galactopoietic hormone. For maintenance of effective and continuous lactation, suckling is essential. It is not only essential for the removal of milk from the glands, but it also causes the release of prolactin. Secretion is a continuous process unless suppressed by congestion or emotional disturbances. Milk pressure reduces the rate of production and hence periodic breast feeding is necessary to relieve the pressure which in turn maintains the secretion.
Breast milk for premature infant is beneficial by many ways (psychological, nutritional and immunological). Metabolic disturbances like azotemia, hyper amnioacidemia and metabolic acidosis are less with breast milk compared to formula. It gives immunological protection to the premature infant.
Percentage composition of colostrum and breast milk
Protein
|
Fat
|
Carbohydrate
|
Water
|
|
Colostrum
Breast milk
|
8.6
1.2
|
2.3
3.2
|
3.2
7.5
|
86
87
|
Advantages -
- The antibodies provides immunological defence to new born.
- It has laxative action on the baby because of large fat globules.
Physiology of lactation -
Although lactation starts following delivery, the preparation for effective lactation starts during pregnancy. The physiological basis of lactation is divided into four phages:
a) Preparation of breast (Mammogenesis).
b) Synthesis and secretion from the breast alveoli (Lactogenesis).
c) Ejection of milk (Galactokinesis).
d) Maintenance of lactation (Galactopoiesis).
Mammogenesis -
Pregnancy is associated with a remarkable growth of both the ductal and lobulo-alveolar systems. An intact nerve supply is not essential for the growth of the mammary gland during pregnancy.
Lactogenesis -
Milk secretion actually starts on 3rd or 4th day after delivery. Around this time, the breasts become engorged, tense, tender and feel warm. Inspite of a high prolactine level during pregnancy, milk secretion is kept in abeyance. Probably, the steroids estrogen and progesterone circulating during pregnancy make the breast tissue unresponsive to prolactin. When the estrogen and progesterone are withdrawn following delivery, prolactin begins its milk secretory activity in previously fully developed mammary glands.
Galactogenesis -
Discharge of milk from the mammary glands depends not only on the suction exerted by the baby during suckling but also on the contractile mechanism which expresses the milk from the alveoli into the ducts.
During suckling, a conditioned reflex is set up. The ascending tackle impulses from the nipple and areola pass via hypothalamus to synthesize and transport oxytocin to the posterior pituitary. Oxytocin produces contraction of the myopithelial cells of the alveoli and the ducts containing the milk. This is the 'milk ejection' or 'milk let down' reflex the milk is forced down into the ampulla of the lactiferous ducts, wherefrom it can be expressed by the mother or sucked out by the baby.
Galactopoiesis -
Prolactin appears to be the single most important galactopoietic hormone. For maintenance of effective and continuous lactation, suckling is essential. It is not only essential for the removal of milk from the glands, but it also causes the release of prolactin. Secretion is a continuous process unless suppressed by congestion or emotional disturbances. Milk pressure reduces the rate of production and hence periodic breast feeding is necessary to relieve the pressure which in turn maintains the secretion.
Breast milk for premature infant is beneficial by many ways (psychological, nutritional and immunological). Metabolic disturbances like azotemia, hyper amnioacidemia and metabolic acidosis are less with breast milk compared to formula. It gives immunological protection to the premature infant.
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