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Question 1:
What is the primary hormone responsible for the synthesis and secretion of breast milk?
A) Estrogen
B) Progesterone
C) Prolactin
D) Oxytocin
Answer: C) Prolactin
Rationale: Prolactin is the key hormone that stimulates mammary gland ductal growth,
epithelial cell proliferation, and milk protein synthesis. It is released from the anterior
pituitary gland in response to nipple stimulation. Estrogen and progesterone inhibit milk
production during pregnancy, and oxytocin is responsible for the milk ejection reflex.
Question 2:
What hormone is responsible for the milk ejection (let-down) reflex?
A) Prolactin
B) Oxytocin
C) Estrogen
D) Progesterone
Answer: B) Oxytocin
Rationale: Oxytocin causes contraction of the myoepithelial cells surrounding the
alveoli, forcing milk from the alveolar lumens into the ducts and out through the nipple.
This is known as the let-down reflex and is triggered by tactile stimulation of the nipple-
areolar complex during suckling.
Question 3:
What event triggers the onset of copious milk production (Stage II lactogenesis)?
,A) The onset of labor
B) Delivery of the placenta
C) The first breastfeeding session
D) Decreased prolactin levels
Answer: B) Delivery of the placenta
Rationale: Stage II lactogenesis, the onset of copious milk production, is triggered by
the delivery of the placenta, which causes a rapid drop in progesterone levels. This drop,
combined with elevated levels of prolactin, cortisol, and insulin, stimulates milk
production. Typically, mothers experience this on days 2 or 3 postpartum.
Question 4:
How does breast milk production primarily regulate itself after lactation is established?
A) By the mother's caloric intake
B) By the feedback inhibitor of lactation (FIL)
C) By the infant's gestational age
D) By maternal stress levels
Answer: B) By the feedback inhibitor of lactation (FIL)
Rationale: Once lactation is established, milk production is primarily regulated by a
feedback inhibitor of lactation (FIL). If milk is not removed, FIL accumulates, reducing
milk production. If milk is removed, the inhibitor is also removed, and secretion will
resume. The amount of milk produced is determined by how much is removed by the
infant, matching supply to demand.
Question 5:
Which of the following is TRUE regarding colostrum?
A) It is high in fat and low in protein
B) It is produced beginning at postpartum day 10
C) It is rich in immunoglobulins, particularly IgA
D) It is produced in large volumes, up to 1.5 liters per day
Answer: C) It is rich in immunoglobulins, particularly IgA
, Rationale: Colostrum is a thick, yellowish fluid produced in the first 48-72 hours
postpartum. It is high in protein, especially immunoglobulins (IgA), but lower in fat and
glucose than mature milk. Only a small volume is produced, but it provides vital passive
immunity to the newborn and has a laxative effect to help clear meconium.
Question 6:
Fore milk differs from hind milk in that:
A) Fore milk is richer in fat
B) Hind milk is watery and high in lactose
C) Hind milk is delivered at the beginning of a feed and quenches thirst
D) Fore milk is delivered at the beginning of a feed and is rich in lactose and protein
Answer: D) Fore milk is delivered at the beginning of a feed and is rich in lactose
and protein
Rationale: Mature milk changes from the beginning to the end of a feed. Fore milk is
the watery, translucent milk at the start of a feeding, rich in lactose and protein to
quench the infant's thirst. Hind milk is delivered toward the end, is opaque and creamy,
and is rich in fat to satisfy the infant's appetite.
Question 7:
From a physiological perspective, what is the clinical significance of the lactiferous
sinuses?
A) They are the primary site of milk synthesis
B) They are where milk is stored before it is ejected during a feed
C) They are the primary site for oxytocin production
D) They are responsible for producing the feedback inhibitor of lactation
Answer: B) They are where milk is stored before it is ejected during a feed
Rationale: Milk is synthesized in the alveoli and then transported through lactiferous
ducts to the lactiferous sinuses. These sinuses are located just beneath the areola and
act as a storage reservoir for milk before it is expelled through the nipple pores during
the let-down reflex.