Certified Lactation Specialist Lactation Specialist Anatomy & Physiology of Lactation 1 — Questions and Answers
Question 1: What are the primary milk-producing secretory cells in the breast alveoli called?
- Myoepithelial cells
- Lactocytes (alveolar epithelial cells) (Correct answer)
- Ductal epithelial cells
- Stromal fibroblasts
Correct answer: Lactocytes (alveolar epithelial cells)
Lactocytes, also called alveolar epithelial cells, are the specialized secretory cells lining the alveoli that synthesize and secrete milk components.
Question 2: Which hormone is primarily responsible for driving milk synthesis (galactopoiesis) during established lactation?
- Estrogen
- Progesterone
- Prolactin (Correct answer)
- Oxytocin
Correct answer: Prolactin
Prolactin, secreted by the anterior pituitary gland in response to suckling, is the primary hormone driving ongoing milk synthesis.
Question 3: What is the primary physiologic role of oxytocin in breastfeeding?
- Stimulating milk synthesis in the alveoli
- Triggering the milk ejection (let-down) reflex (Correct answer)
- Increasing prolactin secretion from the pituitary
- Suppressing progesterone post-delivery
Correct answer: Triggering the milk ejection (let-down) reflex
Oxytocin, released from the posterior pituitary, causes myoepithelial cells surrounding alveoli to contract, propelling milk through the ducts in what is called the milk ejection reflex.
Question 4: During pregnancy, full milk production is suppressed primarily by elevated levels of which hormone?
- Prolactin
- Progesterone (Correct answer)
- Cortisol
- Human placental lactogen
Correct answer: Progesterone
High progesterone levels during pregnancy block prolactin receptor activity on lactocytes, inhibiting copious milk secretion despite rising prolactin.
Question 5: Which structures transport milk from the alveoli toward the nipple openings?
- Cooper's ligaments
- Lactiferous ducts (Correct answer)
- Montgomery glands
- Retromammary space
Correct answer: Lactiferous ducts
Lactiferous ducts form a branching network that collects milk from the alveolar lobules and channels it to the nipple pores for delivery to the infant.
Question 6: Which of the following can inhibit the milk ejection (let-down) reflex?
- Frequent infant suckling
- Stress and elevated catecholamine levels (Correct answer)
- Warm compresses applied to the breast
- Infant skin-to-skin contact
Correct answer: Stress and elevated catecholamine levels
Stress hormones such as epinephrine cause vasoconstriction and can antagonize oxytocin action at the myoepithelial cells, inhibiting let-down.
Question 7: Which phase of lactogenesis refers specifically to the onset of copious milk secretion after delivery?
- Lactogenesis I
- Lactogenesis II (Correct answer)
- Lactogenesis III
- Galactorrhea phase
Correct answer: Lactogenesis II
Lactogenesis II occurs approximately 30-40 hours postpartum when progesterone withdrawal allows prolactin to stimulate large-volume milk production — commonly described as milk 'coming in.'
Certified Lactation Specialist Lactation Specialist Anatomy & Physiology of Lactation 1
What are the primary milk-producing secretory cells in the breast alveoli called?