09/08/2026
Signal Transmission
Sucking stimulates ni**le nerve endings.
Nerves send messages to the brain.
The pituitary gland receives signals.
2. Milk Production (Prolactin)
The brain releases prolactin.
Prolactin targets milk-making cells (alveoli).
Cells pull nutrients from blood.
Alveoli create new breastmilk.
More sucking increases prolactin levels.
3. Milk Delivery (Oxytocin)
The brain releases oxytocin.
Oxytocin contracts muscle cells in breasts.
Milk squeezes into the ducts.
Milk moves toward the ni**le.
This is the "let-down" reflex.
The Role of Breast Emptying
Feedback Inhibitor of Lactation (FIL)
Breastmilk contains a whey protein called FIL.
FIL slows down milk synthesis.
Accumulated milk keeps FIL levels high.
High FIL signals cells to stop.
Emptying the breast removes FIL.
Low FIL triggers rapid production.
Fat Content Regulation
Sucking drains the breast completely.
Empty breasts yield high-fat hindmilk.
Frequent emptying maintains fast refills.