Final answer:
Prolactin, produced by the anterior pituitary gland, is the hormone responsible for promoting milk synthesis. It is regulated by a positive feedback mechanism initiated by the act of breastfeeding or pumping.
Step-by-step explanation:
Milk synthesis is promoted by prolactin, a hormone produced by the anterior pituitary gland. This pituitary hormone is essential in establishing and maintaining the supply of breast milk. Moreover, it plays a vital role in the mobilization of maternal micronutrients for breast milk.
The regulation of prolactin involves a positive feedback loop, which is initiated when a baby suckles on the mother's breast. The stimulation of the nipples sends nerve impulses to the hypothalamus, which in turn stimulates the anterior pituitary to secrete prolactin. As prolactin circulates in the bloodstream, it reaches the mammary glands and stimulates them to produce milk. Frequent breastfeeding or pumping ensures high levels of circulating prolactin, which is crucial for the continued synthesis of milk over time.