Free CLC Development & Physiology of Lactation Questions and Answers — Questions and Answers
Question 1: Which hormone is primarily responsible for milk ejection (let-down)?
- Prolactin
- Estrogen
- Oxytocin (Correct answer)
- Progesterone
Correct answer: Oxytocin
Oxytocin is the hormone primarily responsible for the milk ejection reflex, commonly known as 'let-down.' When a baby suckles, nerve endings in the nipple send signals to the brain, stimulating the release of oxytocin. This hormone causes the myoepithelial cells around the milk-producing alveoli to contract, pushing milk down the ducts and out of the nipple, making it available to the infant.
Question 2: What stage of lactogenesis begins after the delivery of the placenta?
- Lactogenesis I
- Lactogenesis II (Correct answer)
- Lactogenesis III
- Galactopoiesis
Correct answer: Lactogenesis II
Lactogenesis II, often referred to as 'the coming in of milk,' is the stage of milk production that begins after the delivery of the placenta. The sudden drop in progesterone levels following placental expulsion, combined with high prolactin levels, triggers the copious production of mature milk. This typically occurs between 30 and 72 hours postpartum, marking a significant increase in milk volume.
Question 3: Where is milk primarily produced within the breast?
- Lactiferous ducts
- Alveoli (Correct answer)
- Montgomery glands
- Areola
Correct answer: Alveoli
Within the breast, milk is primarily produced in the alveoli, which are tiny, grape-like sacs located in the mammary glands. These specialized cells absorb nutrients from the bloodstream and convert them into breast milk. The milk then collects in the lumen of the alveoli before being transported through the ducts.
Question 4: Which hormone stimulates milk production?
- Oxytocin
- Prolactin (Correct answer)
- Estrogen
- Testosterone
Correct answer: Prolactin
Prolactin is the primary hormone responsible for stimulating milk production (lactogenesis) in the mammary glands. It is released from the anterior pituitary gland in response to nipple stimulation during breastfeeding. While other hormones like oxytocin are involved in milk ejection, prolactin specifically drives the synthesis of milk.
Question 5: What is the function of Montgomery glands?
- Milk production
- Nerve stimulation
- Nipple lubrication (Correct answer)
- Oxytocin storage
Correct answer: Nipple lubrication
Montgomery glands are small sebaceous glands located on the areola, the pigmented area around the nipple. Their primary function is to secrete an oily substance that lubricates and protects the nipple and areola. This secretion also contains antibacterial properties and olfactory cues that may help guide the infant to the breast.
Question 6: What triggers the secretion of prolactin during breastfeeding?
- Infant crying
- Milk fullness
- Breast massage
- Nipple stimulation (Correct answer)
Correct answer: Nipple stimulation
Nipple stimulation is the primary trigger for the release of prolactin, the hormone responsible for milk production. When an infant suckles at the breast, nerve impulses are sent to the brain, signaling the pituitary gland to release prolactin. This reflex ensures that milk supply is maintained in response to the baby's feeding demands.
Question 7: Which structure transports milk from alveoli to the nipple?
- Alveoli
- Areola
- Lactiferous ducts (Correct answer)
- Montgomery glands
Correct answer: Lactiferous ducts
After milk is produced in the alveoli, it travels through a network of small tubes called lactiferous ducts. These ducts converge and widen into lactiferous sinuses, which then open onto the nipple. Their function is to transport the synthesized milk from the production sites to the outside of the breast for the infant to consume.
Question 8: What marks the beginning of lactogenesis I?
- Birth of the infant
- Second trimester (Correct answer)
- Ovulation
- First menstruation
Correct answer: Second trimester
Lactogenesis I, also known as secretory differentiation, is the stage of milk production that begins around the middle of pregnancy, typically in the second trimester. During this phase, the mammary glands develop the capacity to produce milk, and colostrum, the first milk, begins to be formed. This process is largely driven by hormonal changes, even though milk release is inhibited until after birth.
Question 9: Which factor can negatively affect oxytocin release during breastfeeding?
- Calm environment
- Nipple stimulation
- Frequent feedings
- Maternal stress (Correct answer)
Correct answer: Maternal stress
Oxytocin, the hormone responsible for the milk ejection reflex (let-down), is highly sensitive to a mother's emotional state. Stress, anxiety, pain, or embarrassment can inhibit the release of oxytocin, making it difficult for milk to flow freely. A calm and supportive environment, conversely, promotes oxytocin release and efficient milk transfer.
Free CLC Development & Physiology of Lactation Questions and Answers
Which hormone is primarily responsible for milk ejection (let-down)?