Quick revision: every question with its correct answer. For the full explanation, open the test and tap View Solution.
9.5 Pregnancy, Parturition & Lactation — Test 1
Q1. The hormone detected by pregnancy tests is:✓ Human chorionic gonadotropin (hCG)
Q2. hCG maintains early pregnancy by:✓ Rescuing the corpus luteum so it keeps secreting progesterone
Q3. hCG is structurally a heterodimer with:✓ A smaller common alpha and a larger specific beta subunit
Q4. The hormone responsible for maintaining pregnancy (the 'pregnancy hormone') is:✓ Progesterone
Q5. Human placental lactogen (hPL/human chorionic somatomammotropin) acts to:✓ Decrease maternal insulin sensitivity (sparing glucose for the fetus)
Q6. During pregnancy, lactation does NOT occur despite high prolactin because:✓ High estrogen and progesterone block prolactin's action on the breast
Q7. Match each hormone with its role in pregnancy/lactation and choose the correct option.✓ A-iii, B-i, C-ii
Q8. Parturition involves a positive-feedback loop in which:✓ Cervical stretch increases oxytocin, strengthening contractions and stretch
Q9. Oxytocin's role in lactation is to cause:✓ Milk ejection (let-down) by contracting myoepithelial cells
Q10. Prolactin's role in lactation is to:✓ Stimulate milk synthesis
Q11. During lactation, ovulation is often suppressed because prolactin:✓ Inhibits GnRH (and gonadotropin action)
Q12. In late pregnancy, the uterus becomes more responsive to oxytocin because:✓ Oxytocin receptors are upregulated near term
Q13. Estriol, which rises markedly in pregnancy, is produced by the:✓ Fetoplacental unit
Q14. hCG appears in maternal blood approximately:✓ About 6 days after conception (and in urine ~14 days)
Q15. The decline in progesterone's restraining effect near term helps labour by:✓ Allowing increased uterine contractility
Q16. Both prolactin and oxytocin are increased by:✓ Suckling (a neuroendocrine reflex)
Q17. After delivery, lactation begins because:✓ Estrogen and progesterone fall, releasing prolactin's effect on the breast
Q18. Human placental lactogen is structurally related to:✓ Growth hormone and prolactin
Q19. Relaxin during pregnancy/parturition helps by:✓ Softening the cervix and relaxing the pelvic ligaments
Q20. The overall hormonal control of lactation is best summarised as:✓ Prolactin for synthesis, oxytocin for ejection, after steroid withdrawal at delivery