IBLCE Anatomy and Physiology of Lactation

Question 1

Which hormone is primarily responsible for milk synthesis and secretion in the lactating breast?

Accepted Answer

Prolactin

Answer

Prolactin, secreted by the anterior pituitary, is the primary hormone driving milk synthesis (lactogenesis) in the alveolar cells.

Question 2

Which hormone triggers the milk ejection reflex (let-down) by causing myoepithelial cells to contract?

Accepted Answer

Oxytocin

Answer

Oxytocin, released from the posterior pituitary, causes myoepithelial cells surrounding the alveoli to contract, ejecting milk into the ducts.

Question 3

The functional milk-producing unit of the breast is called the:

Accepted Answer

Alveolus

Answer

The alveolus is the microscopic sac lined with secretory epithelial cells (lactocytes) where milk is synthesized and stored.

Question 4

During pregnancy, high levels of which hormone inhibit full lactogenesis despite rising prolactin levels?

Accepted Answer

Progesterone

Answer

High progesterone levels during pregnancy block prolactin receptors on alveolar cells, preventing full milk production until progesterone falls after placental delivery.

Question 5

Lactogenesis II, the onset of copious milk production, typically occurs how many hours after birth?

Accepted Answer

30–73 hours

Answer

Lactogenesis II generally begins 30–73 hours postpartum, corresponding to the drop in progesterone after placental delivery and the surge in prolactin activity.

IBLCE - International Board of Lactation Consultant Examiners Practice Test

IBLCE - International Board of Lactation Consultant Examiners Practice Test

IBLCE Anatomy and Physiology of Lactation