Lactation Physiology & Anatomy Flashcards

What is the primary hormonal trigger for the onset of lactogenesis II after birth?

Answer: The rapid drop in progesterone after delivery of the placenta

Delivery of the placenta causes progesterone to fall, removing its inhibition of prolactin's milk-producing action.

A mother on day 5 postpartum reports no breast fullness and heavy bleeding with clots. Which condition should the counselor suspect may be delaying her milk coming in?

Answer: Retained placental fragments

Retained placental tissue keeps progesterone elevated, which can delay lactogenesis II.

Which mechanism best explains why a full breast slows its own rate of milk synthesis?

Answer: A whey protein called feedback inhibitor of lactation (FIL) accumulates

FIL accumulates in retained milk and locally down-regulates milk production, an autocrine control.

What is the main function of the Montgomery glands on the areola?

Answer: Secreting an oily substance that lubricates the nipple and provides a scent cue for the infant

Montgomery glands secrete a protective, antibacterial lubricant whose scent may help guide the newborn to the breast.

Which structures provide the primary suspensory support for breast tissue?

Answer: Cooper's ligaments

Cooper's ligaments are fibrous bands that connect the breast to the skin and underlying fascia.

Which cells surround the alveoli and contract to push milk into the ducts?

Answer: Myoepithelial cells

Myoepithelial cells contract in response to oxytocin, squeezing milk out of the alveoli.

When does lactogenesis I (secretory differentiation) typically begin?

Answer: Around mid-pregnancy

Lactogenesis I begins around mid-pregnancy, when the breast starts producing small amounts of colostrum.