Physiology of lactation Flashcards
Where is milk made?
In the acini cells (lactocytes) under the influence of the hormone prolactin
Synthesised from glucose and amino acids in the blood stream
Secreted from the acini cell, across the cell membrane, into the lumen of the alveoli
How is prolactin initiated?
Produced in pregnancy but milk production is suppressed by oestrogen and progesterone (placental hormones)
Once the placenta is birthed, the prolactin activates milk production in the acini cells
When are where is prolactin released?
Released from the anterior pituitary gland
Prolactin levels are higher at night time
Released when the baby suckles
How does the baby stimulate milk production?
Nerve in the nipple —> hypothalamus —> anterior pituitary gland —> prolactin —> acini cells —> milk production
Why is prolactin important besides breastmilk?
Produces calmness and reduces stress
Stimulates mothering behaviour
Triggered through tough
What is needed for milk production to be stimulated and maintained?
Early and frequent access to the breast
What is the prolactin receptor theory?
Prolactin receptor sites open when placenta is delivered
Prolactin surges ‘prime’ sites to begin milk production
Receptor sites start to close if not primed
Skin contact and lots of feeds in early days increase potential for long-term milk production
What does oxytocin do?
Works on muscle (myo-epithelial) cells to expel milk
Pulsation action
Induces feelings of love and wellbeing
Can be temporarily inhibited by stress
Creates a feeling of wellbeing
Levels are higher when baby is near
What is endogenous oxytocin?
Natural oxytocin
Crosses the blood-brain barrier
Evokes feelings of love and protectiveness
Stimulated by nurture and tough
What is synthetic oxytocin?
Does not cross the blood brain barrier
Does not evoke the same feelings of love and protectiveness
What is the milk ejection reflex?
Neuro-endocrine reflex
Tactile stimulation of the breast stimulates release of oxytocin front eh posterior pituitary
Oxytocin stimulates contraction of the myo-epithelial cells surrounding the alveoli
Milk is forced into the lactiferous ducts
Initially an unconditioned reflex - later comes a conditioned reflex
What is FIL?
Feedback inhibitor of lactation
Secreted as part of milk
Build-up of FIL blocks milk production
Removing FIL allows milk production
What does the endocrine control of lactation involve?
Pituitary gland
Oxytocin - milk ejection (for this feed)
Prolactin - milk production (for next feed)
Systemic (both breasts)
What does autocrine control of lactation involve?
Feedback inhibitor of lactation
Build-up - inhibits production
Removal - stimulates production
Local (one breast)
How can we enable lactation and breastfeeding?
Keep mother and baby together
Help mothers to recognise feeding cues
Allow unrestricted, frequent feeds
Support mothers to breastfeed at night
Avoid supplements
Use dummies with caution
