🌿 UNIT VI: Reproduction 🌿
CH 2: Human Reproduction
Concepts: Lactation
1. Lactation refers to:
A. Formation of placenta
B. Secretion of milk by mammary glands
C. Fertilization of ovum
D. Expulsion of fetus
Answer: B
Explanation: Lactation is the process of milk secretion by mammary glands to nourish the newborn.
2. The first milk produced after childbirth is called:
A. Colostrum
B. Mature milk
C. Transitional milk
D. Formula milk
Answer: A
Explanation: Colostrum is secreted during the first 2–3 days after childbirth and is rich in antibodies.
3. Colostrum is rich in:
A. Fats
B. Antibodies (IgA)
C. Carbohydrates
D. Vitamin D
Answer: B
Explanation: Colostrum contains high levels of IgA, which provides passive immunity to the newborn.
4. Which hormone stimulates milk production?
A. Oxytocin
B. Prolactin
C. Progesterone
D. Estrogen
Answer: B
Explanation: Prolactin from the anterior pituitary stimulates milk synthesis in mammary alveoli.
5. Which hormone is responsible for milk ejection (let-down reflex)?
A. Progesterone
B. Oxytocin
C. hCG
D. Prolactin
Answer: B
Explanation: Oxytocin causes contraction of myoepithelial cells, leading to milk ejection.
6. Mammary glands are:
A. Modified sweat glands
B. Modified sebaceous glands
C. Modified hair follicles
D. Modified salivary glands
Answer: A
Explanation: Mammary glands are modified sweat glands specialized for milk secretion.
7. The ducts that carry milk from alveoli to nipple are called:
A. Alveolar ducts
B. Lactiferous ducts
C. Milk canals
D. Mammary sinuses
Answer: B
Explanation: Lactiferous ducts transport milk from alveoli to the nipple.
8. Temporary storage of milk occurs in:
A. Alveoli
B. Lactiferous sinuses
C. Mammary ducts
D. Areola
Answer: B
Explanation: Lactiferous sinuses act as temporary storage sites for milk.
9. Milk production during pregnancy is inhibited by:
A. Progesterone
B. Prolactin
C. Oxytocin
D. Relaxin
Answer: A
Explanation: High progesterone levels during pregnancy inhibit milk secretion.
10. Milk secretion resumes after childbirth because:
A. Progesterone levels drop
B. Estrogen levels increase
C. Oxytocin is secreted
D. hCG levels increase
Answer: A
Explanation: A fall in progesterone allows prolactin to stimulate milk production.
11. Oxytocin release is triggered by:
A. Placental hormones
B. Suckling by the baby
C. Prolactin secretion
D. Progesterone drop
Answer: B
Explanation: Suckling stimulates sensory nerves that trigger oxytocin release.
12. Positive feedback in lactation refers to:
A. More suckling → more oxytocin → more milk ejection
B. Prolactin inhibits milk production
C. Estrogen suppresses lactation
D. Progesterone increases lactation
Answer: A
Explanation: Increased suckling enhances hormone release, increasing milk ejection.
13. Which hormone prepares mammary glands for lactation?
A. hPL
B. hCG
C. Oxytocin
D. Prolactin
Answer: A
Explanation: Human placental lactogen prepares mammary glands for milk synthesis.
14. The main carbohydrate in milk is:
A. Glucose
B. Lactose
C. Sucrose
D. Maltose
Answer: B
Explanation: Lactose is the primary carbohydrate and energy source in milk.
15. Milk fat serves as:
A. Energy source
B. Antibody
C. Hormone
D. Mineral
Answer: A
Explanation: Milk fat provides energy essential for infant growth.
16. Proteins in milk aid in:
A. Digestion
B. Energy storage
C. Growth and tissue repair
D. Immunity only
Answer: C
Explanation: Milk proteins support growth and tissue repair in the newborn.
17. The first phase of lactation is:
A. Colostral phase
B. Transitional phase
C. Mature milk phase
D. Lactogenic phase
Answer: A
Explanation: The colostral phase lasts for 2–3 days after childbirth.
18. The second phase of lactation is:
A. Colostral
B. Transitional
C. Mature milk
D. Post-lactation
Answer: B
Explanation: Transitional milk forms between colostrum and mature milk.
19. Mature milk is produced after:
A. 1–2 days
B. 10 days
C. 2 weeks
D. 1 month
Answer: B
Explanation: Mature milk production begins around the 10th day postpartum.
20. Which antibody provides passive immunity to newborn?
A. IgA
B. IgG
C. IgM
D. IgE
Answer: A
Explanation: IgA protects mucosal surfaces of the newborn.
21. Milk also contains:
A. Enzymes
B. Hormones
C. Vitamins and minerals
D. All of the above
Answer: D
Explanation: Human milk contains enzymes, hormones, vitamins, and minerals.
22. The let-down reflex is mediated by:
A. Hypothalamus and posterior pituitary
B. Anterior pituitary
C. Corpus luteum
D. Placenta
Answer: A
Explanation: Oxytocin release is controlled by hypothalamus and posterior pituitary.
23. Suckling maintains milk production through:
A. Negative feedback
B. Positive feedback
C. Hormonal inhibition
D. Placental signals
Answer: B
Explanation: Increased suckling enhances prolactin and oxytocin secretion.
24. Lactation promotes uterine contraction due to:
A. Prolactin
B. Oxytocin
C. Estrogen
D. hCG
Answer: B
Explanation: Oxytocin contracts uterine muscles, aiding involution.
25. Milk is expelled from alveoli by contraction of:
A. Smooth muscle cells
B. Myoepithelial cells
C. Skeletal muscle
D. None
Answer: B
Explanation: Myoepithelial cells contract under oxytocin influence.
26. Colostrum is rich in:
A. Lactose
B. Immunoglobulins
C. Fat
D. Hormones
Answer: B
Explanation: Immunoglobulins provide immune protection to newborns.
27. Human milk is:
A. Hypotonic
B. Isotonic
C. Hypertonic
D. None
Answer: B
Explanation: Isotonic milk is easy for infants to digest.
28. Lactation is controlled by:
A. Nervous system only
B. Endocrine system only
C. Both nervous and endocrine systems
D. None
Answer: C
Explanation: Lactation involves neural reflexes and hormonal control.
29. Milk synthesis occurs in:
A. Lactiferous ducts
B. Alveoli
C. Nipple
D. Areola
Answer: B
Explanation: Alveoli are the milk-producing structures.
30. Milk ejection occurs through:
A. Lactiferous ducts
B. Alveoli
C. Nipple
D. Areola
Answer: C
Explanation: Milk exits the breast through the nipple.
31. Lactation helps in:
A. Infant nutrition
B. Immunity transfer
C. Mother–infant bonding
D. All of the above
Answer: D
Explanation: Lactation provides nutrition, transfers antibodies, and strengthens emotional bonding between mother and infant.
32. Human milk contains which fatty acid important for brain development?
A. Linoleic acid
B. DHA (Docosahexaenoic acid)
C. Palmitic acid
D. Stearic acid
Answer: B
Explanation: DHA is essential for brain and retinal development in infants.
33. Milk protein casein helps in:
A. Calcium absorption
B. Immunity
C. Energy production
D. Hormone regulation
Answer: A
Explanation: Casein binds calcium and helps in bone and teeth development.
34. Milk secretion after childbirth is:
A. Continuous and automatic
B. Dependent on suckling
C. Independent of hormones
D. Only mechanical
Answer: B
Explanation: Continued suckling maintains prolactin and oxytocin secretion, sustaining milk production.
35. Which hormone increases alveolar cells’ sensitivity to prolactin?
A. Estrogen
B. Progesterone
C. Relaxin
D. hCG
Answer: A
Explanation: Estrogen enhances mammary gland growth and responsiveness to prolactin.
36. Lactation is suppressed during pregnancy by:
A. High estrogen
B. High progesterone
C. High prolactin
D. Oxytocin
Answer: B
Explanation: Progesterone inhibits milk secretion despite high prolactin levels during pregnancy.
37. Which structure stores milk before let-down?
A. Alveoli
B. Lactiferous sinuses
C. Nipple
D. Areola
Answer: B
Explanation: Lactiferous sinuses temporarily store milk before ejection.
38. Which hormone prepares mammary glands but inhibits lactation during pregnancy?
A. Estrogen
B. Progesterone
C. Prolactin
D. Oxytocin
Answer: B
Explanation: Progesterone promotes gland development but prevents milk secretion during pregnancy.
39. Milk secretion is maximum in:
A. Morning
B. Evening
C. During night feeding
D. Depends on baby’s demand
Answer: D
Explanation: Milk production depends on frequency and intensity of suckling by the baby.
40. Which enzyme helps in digestion of lactose in newborn?
A. Amylase
B. Lactase
C. Lipase
D. Protease
Answer: B
Explanation: Lactase breaks lactose into glucose and galactose for absorption.
41. Mammary glands are fully functional after:
A. Puberty
B. First menstruation
C. Childbirth
D. Menopause
Answer: C
Explanation: Full functional activity of mammary glands occurs after childbirth.
42. Breastfeeding promotes:
A. Uterine involution
B. Natural contraception
C. Emotional bonding
D. All of the above
Answer: D
Explanation: Breastfeeding releases oxytocin, aiding uterine involution, bonding, and lactational amenorrhea.
43. Which hormone triggers contraction of myoepithelial cells in alveoli?
A. Prolactin
B. Oxytocin
C. Estrogen
D. Progesterone
Answer: B
Explanation: Oxytocin causes contraction of myoepithelial cells, resulting in milk ejection.
44. Lactation ensures transfer of:
A. Passive immunity
B. Growth factors
C. Nutrients
D. All of the above
Answer: D
Explanation: Human milk provides nutrition, immunity, and growth-promoting substances.
45. Human milk is:
A. Easily digestible
B. Rich in antibodies
C. Complete nutrition for newborn
D. All of the above
Answer: D
Explanation: Human milk is easily digestible, antibody-rich, and nutritionally complete.
46. Let-down reflex is an example of:
A. Negative feedback
B. Positive feedback
C. Reflex arc
D. Hormone inhibition
Answer: B
Explanation: Suckling increases oxytocin release, which further enhances milk ejection.
47. The hormone responsible for breast tissue development during pregnancy is:
A. Oxytocin
B. Estrogen
C. Prolactin
D. hCG
Answer: B
Explanation: Estrogen stimulates growth and branching of mammary ducts.
48. The baby’s suckling stimulates which part of the brain?
A. Hypothalamus
B. Cerebellum
C. Medulla
D. Pituitary only
Answer: A
Explanation: Hypothalamus integrates neural signals and regulates oxytocin and prolactin release.
49. Which vitamin in milk is important for calcium absorption?
A. Vitamin A
B. Vitamin D
C. Vitamin K
D. Vitamin C
Answer: B
Explanation: Vitamin D enhances calcium absorption and bone mineralization.
50. Colostrum has:
A. High fat
B. High antibodies
C. Low protein
D. Low minerals
Answer: B
Explanation: Colostrum is rich in antibodies that protect the newborn from infections.
