What does prolactin primarily do in the breasts during lactation?

Prolactin is a hormone primarily responsible for stimulating the production of breast milk during lactation. It is secreted by the anterior pituitary gland, and its levels increase in response to breastfeeding. This hormone promotes the growth of mammary glands and enhances the synthesis of milk components, including lactose and fat, which are crucial for milk production.

The role of prolactin is vital for establishing and maintaining lactation, ensuring that a mother is capable of nourishing her newborn effectively. Increased prolactin levels during suckling signal the body to produce more milk, thus meeting the demands of the infant. This mechanism is essential for breastfeeding success and helps to maintain the mother's supply in response to the baby's needs.

In contrast, regulating milk ejection is primarily the role of oxytocin, while inhibiting the synthesis of milk and storing it in the ducts do not align with the key functions of prolactin. Therefore, understanding prolactin's role reinforces its critical position in lactation and breast milk production.