Which hormone is primarily responsible for milk secretion in lactating mammals?

Which hormone is primarily responsible for milk secretion in lactating mammals?

• A. Estrogen
• B. Testosterone
• C. Prolactin
• D. Insulin

Answer: (C)

Milk production is driven primarily by prolactin, a hormone from the anterior pituitary that signals the mammary glands to synthesize and secrete milk. Suckling reduces dopamine’s inhibition, allowing prolactin to rise and stimulate milk production. Estrogen and progesterone mainly prepare the gland during pregnancy and can suppress milk secretion until after birth when their levels fall. Insulin supports energy for production but isn’t the primary driver, and testosterone isn’t a major regulator of lactation. The actual ejection of milk is controlled by oxytocin, not the production process. So, the hormone responsible for milk secretion is prolactin.

Milk production is driven primarily by prolactin, a hormone from the anterior pituitary that signals the mammary glands to synthesize and secrete milk. Suckling reduces dopamine’s inhibition, allowing prolactin to rise and stimulate milk production. Estrogen and progesterone mainly prepare the gland during pregnancy and can suppress milk secretion until after birth when their levels fall. Insulin supports energy for production but isn’t the primary driver, and testosterone isn’t a major regulator of lactation. The actual ejection of milk is controlled by oxytocin, not the production process. So, the hormone responsible for milk secretion is prolactin.