Physiology of Lactation

Lactation

1. Classroom teaching on Breastfeeding Prepared by: Kalpana Kawan Roll no. 06 BNS 2nd year Teaching and learning practicum

2. General objective At the end of this session, Bsc 3rd year students will be able to explain about Breastfeeding.

3. Specific objectives At the end of this session, Bsc Nursing 3rd year students will be able to: review the anatomy of breast. explain the physiology of lactation. define breastfeeding. introduce breastfeeding. state the composition of breast milk.

4. Count....... define colostrum. introduce colostrum. state the compostion of colostrum . list the important of colostrum. state the term use for breast milk.

5. Anatomy of breast The human breast are modified sweat glands responsible for lactation. Breast is extended from 2nd to 6th ribs vertically and margin of the sternum to the mid axillary line horizontally . Breast or mammary gland composed of glandular tissue, fibrous connective tissue, adipose tissue.

6. Count........ Different hormones are responsible for the development of the breast and changes that occur during pregnancy. The major hormones affecting breast development and enlargement are estrogen, progesterone and prolactin.

7. Structure of the Human Breast Each breast contains about 20 lobes , each lobes contains several lobules which at the end have alveoli. Alveoli contain acini cells which produce milk and surrounded by myoepithelial cells which contracts and propel the milk out. Small lactiferous ducts, carrying milk from the alveoli unite to form larger ducts, one large duct leaves each lobe and wider to form a lactiferous sinus or ampulla which acts as a temprory reservoir for milk

8. Count...... A lactiferous tubles from each sinus emerges on the surface of the nipple. The nipple, is made up of erectile tissue, is covered by pigmented skin . Surrounding the nipple, in an area of pigmented skin called the areola which contain Montgomery's gland . These sebaceous glands secrete sebum like substance which act as a lubricant during pregnancy and throughout breastfeeding.

9. Count...... The areola extends for a distance of 2.5 cm around the nipple. The breast is supply with blood from the internal and external mammary arteries and branches from the intercostals arteries. Venous blood supply by the branches of thoracic veins and intercostals vein.

10. Physiology of lactation The secretion or production of milk is known as lactation .The hormone which initiates lactation is called prolactin . The physiological basis of lactation is divided into 4 phases : Phase 1 - Preparation of breasts ( mammogenesis) Phase 2 - Synthesis and secretion from breasts alveoli (lactogenesis) Phase 3 - Ejection of milk ( Galactokinesis) Phase 4 - Maintenence of lactation ( Galactopoisis)

11. Physiology of lactation contd........... Phase 1 - Preparation of breasts ( mammogenesis) Pregnancy is associated with remarkable growth of both ductal and lobuloalveolar systems. An intact nerve supply is not essential for growth of the mammary glands during pregnancy.

12. Physiology of lactation contd...... Phase 2 - Synthesis and secretion from breasts alveoli (lactogenesis) Milk secretion actually starts on 3rd and 4th postpartum day. Around this time, the breast become engorged, tense, tender and feel warmth . Inspite of a high prolactin level during pregnancy, milk secretion is kept in abeyance.

13. Physiology of lactation contd..... . Probably, steroids estrogen and progesterone circulating during pregnancy make the breast tissues unresponsive to prolactin. When the estrogen and progesterone are withdrawn following delivery, prolactin begins its milk secretory activity in previously fully developed mammary glands . The secretory activity is also enhanced directly or indirectly by growth hormone, thyroxine and insulin.

14. Physiology of lactation contd........ Phase 3 - Ejection of milk ( Galactokinesis ) : Oxytocin is the major galactokinetic hormone . 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.

15. Physiology of lactation contd.....

16. Physiology of lactation contd.... Presence of the infant or infant’s cry can induce let down without suckling . A sensation of rise of pressure in the breasts by milk experienced by the mother at the beginning of sucking is called “ draught” .

17. Physiology of lactation contd.... This can also be produced by injection of oxytocin.The milk ejection reflex is inhibited by factors such as pain, anxiety, breast engorgement or adverse psychic condition (depression). The ejection reflex may be deficient for several days following initiation of milk secretion and results in breast engorgement.

18. Physiology of lactation contd..... Phase 4 - Maintenence of lactation (Galactopoiesis ): Prolactin appears to be the single most important galactopoietic hormone . For maintenance of effective and continuous lactation, frequency of suckling (>8/24 hours) is essential.

19. Physiology of lactation contd.....

20. Milk production A healthy mother will produce about 500–800 mL of milk a day to feed her infant. This requires about 700 Kcal/day for the mother, which must be made up from diet or from her body store. For this purpose a store of about 5 kg of fat during pregnancy is essential to make up any nutritional deficit during lactation.

21. Factor affacting Lactation (Review) Following are the factors that enhance lactation Proper positioning of the infant at the breast. If mother is relaxed/comfortable and confident. Think lovingly of baby Frequent feeding. Precautions to avoid sore nipples Avoidance of formula feeding.

22. Contd........ Following can adversely affect the lactation. Maternal factors Stress / Anxiety ( may decrease production and milk ejection reflex) Separartion of mother and child (eg return to work, school) Hormonal imbalance( thyroid gland, Polycystic ovary syndrome)

23. Contd....... Surgery to the breast or nipple. Mother who does not wake up ( drug, alcohol,medication) Poor nutrition of mother. Incorrect position Painful breast

24. Contd....... Infant factor Baby refusing the breastfeeding.( rapid flow, flat nipple,large nipple) Baby sleeping for a long period. ( e.g jaundice, certain medication) Long period between feeding( baby does not wake up at night) Weak suction ( premature baby, sick baby)

25. 13.2 Initiation and management of breast feeding : Benefits to mother and baby Breastfeeding Definition: Breastfeeding is the method of feeding a baby with milk directly from the mother's breast. -Medical Dictionary Breastfeeding , also known as nursing, is the feeding of babies and young children with milk from a women's breast . -Wikipedia

26. Breastfeeding Contd......... Introduction Breastfeeding is the best natural feeding . Breastfeeding is human right . It not only provides a natural opportunity for bonding but also supports the growth and development of the newborn.

27. Breastfeeding contd.... To establish and sustain exclusive breastfeeding for 6 months, WHO and UNICEF recommend: Early initiation of breastfeeding within the first hour of life . Exclusive breastfeeding : the infant only receives breast milk without any additional food or drink , not even water. Breast feeding on demand: as often as the child wants, day and night. No use of bottles , pacifiers.  

28. Mother Milk/ Breast milk Breast milk is complete food for infants . Exclusive breastfeeding meets all the nutritional needs of a baby for the first six months and continue to be a sourse for nutrition and protection with appropriate complementary foods for upto two year of age or beyond . Anti infective properties: Macrophages, lymphocytes and polymorphs, secretary IgA, Lyzozyme, Lactoferrin ( inhibits growth of E.coli) , anti viral agents.

29. Contd......... Composition of breast milk: (per 100ml) Water(g) - 88 Energy(kcal) -65 Protein(g) - 1.1 Carbohydrate(g) -7.4 Fat(g) -3.4

30. Contd...... Calcium (mg) - 28 Phosphorous ( mg - 11 Carotene(microgram) - 137 Thiamine(mg) - 0.02 Riboflavin(mg) - 0.02 Vitamin C(mg) - 3

31. Colostrum " C olostrum is the first immunization for the new born babies”

32. Colostrum Definition: Colostrum is the first form of milk produced by the mammary glands of mammals(including human) immediately following delivery of new born. - Wikipedia

33. Contd....... Introduction Colostrum is the first liquid that is produced in the first few days after delivery. It is the perfect first food for newborns which is considered as an infant’s first immunization. It is yellow, thick and contain more antibodies and white blood cells . Though secreted only in small quantities, it has higher protein content and most suited for the needs of the baby, it should never be discarded.

34. Composition of colostrum (average values per100 ml whole milk) Energy(kcal) - 58 Fat(g) - 2.9 Calcium(mg) -31 Phosphorous(mg)-14 Protein(g) - 2.7 Lactose (g) -5.3 Carotene(IU) -186 vitamin A(IU) -296

35. Important of colostrum Antibody rich : Protects against infection and allergy Many white blood cells Protects against infection Purgative : Clear meconium, help prevent jaundice. Growth factors: Helps intestine mature, prevent allergy, intolerence. Vitamin A rich : Reduces severity of some infection ( such as measles and diarrhoea . Prevent vitamin A related eye diseases.

36. Terms use for different breast 1. Transitional milk It follows the colostrums and secretes during first 2 weeks of postnatal period. It has increase fat and sugar content and decreased protein and immunoglobuline content. At this time breasts feel full, hard and heavy.

37. Contd... 2. Mature milk: It is thiner and watery but contains all the nutrients essential for optimal growth of the baby. Mature milk changes even during the length of a single feed to exactly suit the needs of a baby .

38. Contd....... 3.Preterm milk: It is the breast milk of a mother who deliver prematurely. It is different from milk of a mother who has delivered a full term baby. This milk content more proteins, sodium, iron, immunoglobulin and calories appropriate for the requirement of the preterm neonates. The preterm milk is ideal food for low birth weight babies .

39. Contd..... M ilk changes even during the length of a single feed to exactly suit the needs of a baby. Fore milk: It is the milk secreted at a start of a feed. It is watery and is rich in proteins, sugar, vitamins, minerals and satisfies the baby's thirst.  

40. Contd.......... Hind milk: It comes later in a feed, is rich in fat which make it look whiter and thicker than foremilk. It satisfies the babies hunger and supply much of the energy of a breastfeed. It should be noted that a baby needs both the foremilk and the hind milk for appropriate weight gain. Also , babies who are fed both foremilk and hind milk sleep well .

41. Post - test A) Fill in the blanks 1. .................. is the major galactokinetic hormone. 2. The first immunization for the new born babies is ................

42. Summary

43. Home assignment Read about management of breast feeding.

44. Plan for next class We will discuss about management of breastfeeding