Oxygen & Carbon Dioxide Transport — Respiratory Physiology

Oxygen & Carbon Dioxide Transport MCQs: practice questions

Sample Oxygen & Carbon Dioxide Transport multiple-choice questions from Respiratory Physiology.

1. The amount of dissolved O2 in blood is directly proportional to:

   • A. Hematocrit only
   • B. Hemoglobin concentration only
   • C. PO2
   • D. PCO2
   • E. Bicarbonate concentration

2. The higher O2 affinity of HbF facilitates:

   • A. Transfer of O2 from maternal to fetal blood
   • B. O2 unloading from fetal blood to placenta
   • C. CO2 transport only
   • D. Increased fetal 2,3-DPG binding
   • E. Conversion of Fe2+ to Fe3+

3. In carbon monoxide poisoning, the measured PaO2 may be:

   • A. Always markedly increased
   • B. Always zero
   • C. Relatively normal despite impaired O2 content
   • D. Equal to venous PO2
   • E. Independent of inspired PO2

4. Most oxygen in blood is transported:

   • A. Bound to hemoglobin
   • B. Dissolved in plasma
   • C. As bicarbonate
   • D. As carbaminohemoglobin
   • E. As carbonic acid

5. Carbon monoxide decreases O2 delivery primarily because it:

   • A. Raises hemoglobin concentration
   • B. Binds hemoglobin with high affinity
   • C. Increases dissolved O2
   • D. Raises 2,3-DPG immediately
   • E. Increases tissue blood flow

6. Hypoxemia is defined primarily as:

7. O2 delivery to tissues is calculated as:

8. A rightward shift of the O2-hemoglobin dissociation curve indicates:

9. Which change shifts the O2 dissociation curve to the right?

10. Bicarbonate is transported from RBCs into plasma in exchange for:

11. Anemia is a cause of hypoxia because it causes:

12. Carbonic anhydrase in RBCs catalyzes:

13. The Haldane effect describes the effect of:

14. A leftward shift of the O2-hemoglobin dissociation curve indicates:

15. An increased P50 indicates:

16. Anemia can reduce O2 delivery despite normal PaO2 because:

17. Deoxygenated hemoglobin can carry:

18. Most CO2 is transported in blood as:

19. Cyanide poisoning causes tissue hypoxia because it:

20. Some CO2 is transported bound to hemoglobin as:

21. At a PO2 of 100 mm Hg, dissolved O2 concentration is approximately:

22. The Bohr effect refers to the decrease in hemoglobin O2 affinity caused by:

23. Methemoglobin is unable to:

24. An increase in 2,3-DPG causes:

25. The majority of blood oxygen content is determined by:

26. An increase in temperature shifts the O2-hemoglobin curve:

27. Methemoglobin contains iron in the:

28. P50 is the PO2 at which hemoglobin is:

29. Fetal hemoglobin has:

30. The chloride shift facilitates: