Question

which of the following is needed for milk ejection (letdown) from the breasts?
a prolactin
b oxytocin
c colostrum
d estrogen

Explanation:

Prolactin is mainly for milk production. Colostrum is the first milk secreted. Estrogen is related to sexual development. Oxytocin causes the contraction of the myoepithelial cells around the alveoli in the breast, which is essential for milk ejection (letdown).

Answer:

B. Oxytocin