1. LACTATION

2. Topics to be covered What is lactation Anatomy of the breast
Development of the breast
Histology of the lactating mammary gland
Hormonal control of Breast growth and lactation
Composition of milk

3. What is lactation?
Feeding human breast-milk to provide for the nutritional needs of infants
An alternative to human breast milk is by using formula feeding which is food products designed to provide for the nutritional needs of infants. They include powders, concentrates or ready-to-use forms

4. Milk Formula
Should contain the right balance of nutrients according to the age of the infant or child and formulated as close as possible to breast milk i.e.,
nutrient contents automatically changes with babies’ needs
DHA (Docosahexaenoic Acid), Protein, Sialic acid, choline, taurine, other omega 3 and 6, inulin dietary fibr, calcium, iron, essential vitamins and vital minerals in quantities appropriate for infants and children developmental needs.
Some also contains L Bifidus, a type of friendly and beneficial bacteria found in the intestinal tract which enables the child to obtain all the goodness from food for growth & development.
Available in either regular, honey, mild chocolate or fine cereals
Some powders which are soya based are formulated for lactose intolerance babies. Soya based milk is quite expensive.

5. Examples of milk formula/powder in Malaysia

7. Breast milk is the best!!!!
Milk glands
Proper latching on
Areola

8. Anatomy of breast External structure
Breast situated on the anterior chest wall between 2nd and 6th ribs, extended to the sternum and axilla
In the centre-erectile structure-nipple
Has opening of lactiferous duct.
The areola is area of loose skin with sebaceous gland.

9. Anatomy A. Glandular tissue Produce milk
Internal structure
Mature breast consist of glandular tissue, ductal
tissue, fibrous tissue and fatty tissue
A. Glandular tissue
Produce milk
Acinar secretory cell are arranged to alveolus
Alveolus will form lobules
Lobules will form lobes
There are lobes, each consist of lobules which include alveoli

10. Group of alveoli empty their milk into distal lactiferous duct
B. Ductal tissue
Transport milk
Group of alveoli empty their milk into distal lactiferous duct
Many lactiferous duct units to form major duct.
Each major duct widen to form an ampulla (lactiferous sinus) as it reach the areola
Each ampulla narrow to form separate opening on the nipple

11. C. Fibrous tissue D. Fatty tissue Support the breast
Chest wall superficial fascia condenses to form multiple fascial bands ( Cooper ligaments)
D. Fatty tissue
comprises of 85% of breast
Responsible for bulk and shape

12. Picture 1: Breast structure

13. Formation of mammary glands
During birth, mammary glands consists of sparse alveoli and abundant lactiferous ducts
After puberty, under the influence of estrogen, these ducts will produce branches which ends in polyhedral granular cells that are dense, small and circular (true alveoli)
E and P4 will stimulate the growth of ductal- lobular-alveolar system and breast enlargement with fat deposition and growth of connective tissue

14. Breast changes during pregnancy
Breast hypertrophy occur with pregnancy
Size increase 400g each
Blood flow double
Areola enlarged and pigmented
Montogomery glands becomes prominent.
Increase fat deposition and retention of fluid and electrolyte

15. Hormonal control of breast and lactation
Breast growth during pregnancy is associated with increase levels of oestrogen, progesterone, hPL and prolactin from maternal pituitary
Oestrogen promote duct growth
However alveolar development require full complex of hormones
Oestrogen and progesterone inhibit lactogenic effects of hPL and prolactin
After delivery, rapidly decreasing level of steroidsmilk secretion occur

16. Histology of lactating breast
Alveolar epithelium consists of short columnar cells with microvillous surface
There is a prominent endoplasmic reticulum and golgi apparatus at the base of cells
Both fat droplet and vesicle(lactose&protein) from GA fuse with the cell membrane and discharged into lumen.
Milk are stored alveoli, duct and cistern
When lactation ceases extensive degeneration of lactogenic cells, a phagocytic reaction and fatty tissue infiltration

17. Milk ejection reflex
Suckling stimulates release of prolactin and oxytocin via neurological pathways between nipple and the hypothalamus.
Milk ejection is brought about by the contraction of myometrial cells around the alveoli and ducts under influence of pituitary oxytocin.

20. This sharp increase in prolactin secretion,
diminishes progressively over 3 months of BF
No direct relationship between prolactin level and milk yield
The most important factors are removal of the milkpromotes further milk production
In the absence of suckling, maternal level of prolactin reduced slowly to reach non pregnant value after 2-3 weeks

21. Milk ejection reflex
MER – a neuroendocrine reflex and a conditioned reflex
Apart from touch and pressure on the nipple, stimulation from a baby’s cry for milk, thoughts of your baby and lactation times can cause milk let-down
This conditioned reflex is more for release of oxytocin and not prolactin
Stimulation to vagina and cervix can also cause milk let-down

22. MER can be inhibited due to pain after labour, anxiety and worries whether you are feeding the baby enough
All these will cause inhibition of oxytocin release

23. Fertility during lactation
Some women assumes their menstrual cycle right after puerperium
Some women may have no menses for almost a year or as long as baby is breast- feeding (Prolactin inhibits the hormones for control of regular menstruation)
May be use as a natural contraceptive

24. Advantages of breast milk
Free
Comes at the right temperature
Release on demand
Changes to suit baby’s needs
Comes in an attractive package

25. Stage of lactation(Summary)
Stages
Defination
Onset
Initiating events
Ostrogen, progesterone, prolactin
Mammogenesis
Preparing breast for milk secretion
Puberty
Increasing level of oestrogen and progesterone
Oestrogen
Progesterone
Prolactin, GH, insulin, cortisols
Lactogenesis
Initiation of milk secretion in alveoli
Post partum
Declining O, P, hPL
prolactin
Galactopoiesis
Maintanace of established milk secretion
After each emptying of duct and alveoli
Periodic suckling
Oxytocin prolactin

26. Colostrum
Is a yellow fluid containing fat laden cells and large quantity of protein and minerals.
Secreted first 24 – 48 hours of life
Highest absorption occurs in first 24 hours of life
Contains relatively higher levels of IgG, IgM, and IgA including antibodies to bacteria esp E.coli
After 1st week, predominant IG is secretory IgA

27. Composition of human milk (produced 2 to 3 days post delivery)
Component
Human
Water
85%
Carbohydrate
7% (Lactose)
Protein
1-1.5% (40% casein)
Lipids
3.5% (palmitic, oleic acid)
Enzymes
Amylase, catalase, peroxidase, lipase to help in digestion
Mineral
Vit A abundant
Immunology
IgA protect against enteric bacteria, T and B cell lymphocytes provides active immunity

28. When lactation stops, the involution of the mammary glands occur after three months
Distension and mechanical atrophy occurs to the epithelial
structure, rupture to the alveoli wall and formation of cavities in the mammary tissue
Alveolar distension will cause alveolar hypoxia
After phagocytosis of dead cells, the lobular-acinar structure becomes smaller and the ductular system predominates
The alveolar lumen decreases and dissapears and the surface changes to a double non-secretory layer
Milk production can also be terminated by a lactation depressant using bromocriptine, an agonist receptor Dopamine D2 that inhibits prolactin release

29. Other Breast milk benefit