We can understand the sequence of lactation of mammary gland in the following points

1.Infant suckling stimulates the nerve endings in the nipple and areola, which signal the pituitary gland in the brain to release two hormones, prolactin and oxytocin.

2. Prolactin causes your alveoli to take nutrients (proteins, sugars) from your blood supply and turn them into breast milk.

3. Oxytocin causes the cells around the alveoli to contract and eject your milk down the milk ducts. This passing of the milk down the ducts is called the “let-down” (milk ejection) reflex.

4. Release of the oxytocin hormone while breastfeeding will also cause the uterus to contract. This may be more noticeable if you have previously had children. This mechanism helps your uterus return to its pre-pregnancy size quickly.