Posterior Pituitary (ADH & Oxytocin)

20 questions • 1 test • tap a section to begin

Welcome! 4.5 Posterior Pituitary (ADH & Oxytocin) — 20 questions, CSIR-NET style.

What this test covers

  • ADH: V2 (water) and V1 (vasoconstriction) actions
  • Regulation of ADH; SIADH and diabetes insipidus
  • Oxytocin: suckling, milk ejection, uterine contraction
  • Hypothalamic origin and storage

How to use

  • Tap the test below — it opens on its own full screen. Use ← All tests at the top to come back.
  • Each question has a 40-second timer. Answer, then Submit to see your score.
  • Tap 📋 View Solution under any question for a full explanation.

Open Review at the bottom for a quick revision list of every question with its correct answer.

Quiz
Question Palette
Quiz
Question Palette
Quiz
Explanation:

Quick revision: every question with its correct answer. For the full explanation, open the test and tap View Solution.

4.5 Posterior Pituitary (ADH & Oxytocin) — Test 1
Q1. The renal water-retaining action of ADH is mediated by:✓ V2 receptors and cAMP (inserting aquaporin-2)
Q2. The vasoconstrictor (pressor) action of ADH is mediated by:✓ V1 receptors and the IP3/Ca²⁺ system
Q3. ADH secretion is INCREASED by:✓ Increased serum osmolarity
Q4. Syndrome of inappropriate ADH secretion (SIADH) is associated with:✓ Hyponatremia and water intoxication
Q5. A patient with very dilute urine, high serum osmolarity, and NO response to exogenous ADH most likely has:✓ Nephrogenic diabetes insipidus
Q6. A lung-cancer patient with hypercalcemia develops dilute urine unresponsive to ADH. The likely link is:✓ Hypercalcemia (from PTH-rp) causing nephrogenic diabetes insipidus
Q7. Oxytocin secretion is increased by:✓ Suckling and dilation of the cervix
Q8. Match each ADH receptor with its action and choose the correct option.✓ A-ii, B-i
Q9. The main action of oxytocin on the breast is:✓ Contraction of myoepithelial cells (milk ejection)
Q10. ADH originates primarily in the ___ nucleus, and oxytocin in the ___ nucleus of the hypothalamus.✓ supraoptic; paraventricular
Q11. Oxytocin is used clinically to:✓ Induce labour and reduce postpartum bleeding
Q12. In central diabetes insipidus, the defect is:✓ Deficient ADH secretion (responds to exogenous ADH)
Q13. Factors that DECREASE ADH secretion include:✓ Ethanol and ANP
Q14. Both ADH and oxytocin are:✓ Homologous nonapeptides made in the hypothalamus
Q15. The appropriate treatment for hypercalcemia-induced nephrogenic DI in malignancy is to:✓ Lower serum calcium (e.g. pamidronate plus furosemide)
Q16. In SIADH, the typical laboratory pattern is:✓ Low serum osmolarity with inappropriately concentrated urine
Q17. Oxytocin causes uterine contraction; near term, uterine sensitivity rises because:✓ Oxytocin receptors are upregulated as parturition approaches
Q18. Increased serum osmolarity raises ADH through:✓ Hypothalamic osmoreceptors
Q19. Which best distinguishes central from nephrogenic diabetes insipidus?✓ Response of urine osmolarity to exogenous ADH (responds in central, not nephrogenic)
Q20. Thirst in a patient with diabetes insipidus is best explained by:✓ Rising serum osmolarity from water loss