Respiratory - from West's 8th ed Chapter 4 - Blood Flow and Metabolism

Question 1

1. The ratio of total systemic vascular resistance to pulmonary vascular resistance is about:
A. 2 : 1
B. 3 : 1
C. 5 : 1
D. 10 : 1
E. 20 : 1

Answer 1

D

Question 2

2. Concerning the extra-alveolar vessels of the lung:
   A. Tension in the surrounding alveolar walls tends to narrow them.
   B. Their walls contain smooth muscle and elastic tissue.
   C. They are exposed to alveolar pressure.
   D. Their constriction in response to alveolar hypoxia mainly takes place in the veins.
   E. Their caliber is reduced by lung inflation.

Answer 2

B

Question 3

3. A patient with pulmonary vascular disease has mean pulmonary arterial and venous pressures of 55 and 5 mm Hg, respectively, while the cardiac output is 3 liters per minute. What is his pulmonary vascular resistance in mm Hg/litre/min?
A. 0.5
B. 1.7
C. 2.5
D. 5
E. 17

Answer 3

E

Question 4

4. The fall in pulmonary vascular resistance on exercise is caused by:
   A. Decrease in pulmonary arterial pressure.
   B. Decrease in pulmonary venous pressure.
   C. Increase in alveolar pressure.
   D. Distension of pulmonary capillaries.
   E. Alveolar hypoxia.

Answer 4

D

Question 5

5. In a measurement of cardiac output using the Fick principle, the O2 concentrations of mixed venous and arterial blood are 16 and 20ml / 100ml, respectively, and the O2 consumption is 300 ml/min. The cardiac output in liters/min is:
A. 2.5
B. 5
C. 7.5
D. 10
E. 75

Answer 5

C

Question 6

6. In zone 2 of the lung:
   A. Alveolar pressure exceeds arterial pressure.
   B. Venous pressure exceeds alveolar pressure.
   C. Venous pressure exceeds arterial pressure.
   D. Blood flow is determined by arterial pressure minus alveolar pressure.
   E. Blood flow is unaffected by arterial pressure.

Answer 6

D

Question 7

7. Pulmonary vascular resistance is reduced by:
   A. Removal of one lung.
   B. Breathing a 10% oxygen mixture.
   C. Exhaling from functional residual capacity to residual volume.
   D. Acutely increasing pulmonary venous pressure.
   E. Mechanically ventilating the lung with positive pressure.

Answer 7

D

Question 8

8. Hypoxic pulmonary vasoconstriction:
   A. Depends more on the PO2 of mixed venous blood than alveolar gas.
   B. Is released in the transition from placental to air respiration.
   C. Involves CO2 uptake in vascular smooth muscle.
   D. Partly diverts blood flow from well-ventilated regions of diseased lungs.
   E. Is increased by inhaling low concentrations of nitric oxide.

Answer 8

B

Question 9

9. If the pressures in the capillaries and interstitial space at the top of the lung are 3 and 0 mm Hg, respectively, and the colloid osmotic pressures of the blood and interstitial fluid are 25 and 5 mm Hg, respectively, what is the net pressure in mm Hg moving fluid into the capillaries?
A. 17
B. 20
C. 23
D. 27
E. 33

Answer 9

A

Question 10

10. The metabolic functions of the lung include:
    A. Converting angiotensin II to angiotensin I.
    B. Producing bradykinin.
    C. Secreting serotonin.
    D. Removing leukotrienes.
    E. Generating erythropoietin.

Answer 10

D