lactation

Question 1

what are the major components and functions of human milk

Answer 1

phagocytes, lymphocytes, Tcells
= immunological protection

small soluble signalling molecules e.g. PG, cytokines, GFs
= immunomodulators, promote leucocyte movement, EGF helps gut epithelium growth

enzymes e.g. amylase, lipase
= helps baby digest polysaccharides, hydrolyses fat

lipids, fatty acids, triglycerides
= source of calories, increased visual acuity and cognition

lactose major carbohydrate
= important energy source, galactose impt for myelin synthesis

water
= hydration

Question 2

what are the differences between bovine and human milk

Answer 2

humans take approx 4-6 months to double their birthweight

therefore human milk must be specifically adapted for human requirements

e.g. far more linoleic acid (essential F.A in diet)

Question 3

what is the baby friendly initiative

Answer 3

Scheme launched in 1991 by UNICEF and WHO

aims to promote exclusive breastfeeding

Question 4

drug transmission via breastfeeding

Answer 4

alcohol
- babies dont suckle as well, lead to feeding problems

caffeine
- readily enters and babies cant process as well as adults but normal intake is ok

nicotine
- should be discouraged

Question 5

disease transmission via breastfeeding

Answer 5

• breastfeeding accounts for up to half of all HIV infections
  - formula feeding is a viable alternative
• mastitis
  - infection of lactiferous lobe
  - not an indication to stop though
• Hepatitis B
  - no risk of infection

Question 6

public health benefits (to babe) from breastfeeding

Answer 6

• breastfed babies dont tend to be overfed
• at 12mnths of age breastfed babies are leaner than controls
• may confer a slight protection against childhood obesity
• reduces poor outcomes from infectious disease
• prevents exposure to diarrhoea inducing pathogens and provides protective factors e.g. antibodies
• protects against otitis media, developing atopy, asthma, diabetes, obesity in later life, SIDS

Question 7

colostrum and its differences to mature milk

Answer 7

milk produced in the first days after delivery, is thick

• contains less sugar and less fat than mature milk (less about energy)
• contains more total proteins than mature milk e.g. rich in IgA

Question 8

what is responsible for the onset of lactation

Answer 8

the withdrawal of placental steroids

- E2 and P4 inhibit breast responsiveness to prolactin

Question 9

what does suckling stimulate the release of

Answer 9

suckling stimulus is transmitted to hypothalamus reducing the release of dopamine
- DA prolactin inhibiting substance

suckling also stimulates release of vasoactive intestinal polypeptide (VIP) into portal vessels
- causing prolactin release

Question 10

when does involution occur

Answer 10

approx 40 days after last feed - due to build up of inhibiting substances

Question 11

glactopoiesis

Answer 11

maintenance of established milk secretion

Question 12

lactogenesis stage 2

Answer 12

• PP days 3-8 start of alrge-scale milk production
• increased alpha lactalbumin, decreased Na+ and Cl- in milk
• due to tight junctions in alveolar epithelium