The hormone that causes ejection of milk into the mammary ducts is:
A) prolactin.
B) estrogen.
C) oxytocin.
D) progesterone.

Question

Quizplus · Accepted Answer

The hormone that causes ejection of milk into the mammary ducts is oxytocin. Oxytocin is released from the pituitary gland in response to suckling or stimulation of the nipples. It causes the muscles surrounding the milk-producing cells in the mammary glands to contract, resulting in the release of milk into the ducts. Prolactin is the hormone that stimulates milk production, but it does not cause ejection of milk. Estrogen and progesterone are involved in breast development during pregnancy, but they are not directly involved in milk production or ejection.

The Hormone That Causes Ejection of Milk into the Mammary