Pulmonary Diffusion & Gas Transport

1.

1 point

In a person with a cardiac output of 4L/min, a respiratory rate of 10 breaths/min, an arterio-venous oxygen difference of 4 ml O2/dl, what is their oxygen consumption per minute? (L25, Slide 7)

240 ml O2/min

160 ml O2/min

24 ml O2/min

16 ml O2/min

2.

1 point

Which of the following will cause a left shift in the O2-hemoglobin dissociation curve? (L25, Slide 14)

Increased H+ concentration

Exercise

Increased 2,3 DPG

Increased CO2

None of the Above

All of the above

3.

1 point

At standard alveolar oxygen pressure of 100mmHg, which would increase the amount of Nitrogen dissolved in the blood? (L24, Slide 5 & 6)

Increasing alveolar nitrogen pressure

Decreasing the thickness of the blood-air barrier

Increasing respiratory rate

Increasing heart rate

4.

1 point

Which of the following is NOT a physiologic cause of hyopoxemia? (L24, Slide 8)

patent ductus arteriosus

Breathing into a paper bag

Low heart rate

pulmonary embolism

Low tidal volume

5.

1 point

Which zone of the lung has the highest alveolar volume? (L24, Slide 19)

Lower zone

Middle zone

Upper zone

None of the above

6.

1 point

Which cause of hypoxemia would cause an abnormally high concentration of alveolar O2? (L24, Slide 16)

Pulmonary embolism

Low PiO2

Patent ductus arteriosus

Thickening of the blood-air barrier

7.

1 point

True or False: Tachypnea is defined as an excess supply of oxygen to the alveoli. (L24, correlated with slide 11)

True

False

8.

1 point

True or False: The septic shock oxygen delivery curve has a higher critical extraction ratio than the normal shock oxygen delivery curve. (L25, Slide 9)

True

False

9.

1 point

After treatment with 100% O2 ventilation, which cause of hypoxemia would present with a PaO2 of greater than 500? (L24, Slide 30)

Hypoventilation

Shunt

Perfusion limitations

V/Q=0

10.

1 point

Which of the following will NOT cause an abnormal pulmonary diffusion test? (L25, Slide 17)

Anemia

Smoking

Alveolar bleeding

Carbon monoxide poisoning

All of the above will cause an abnormal test

11.

1 point

True or False: Hypoventilation is ALWAYS associated with hypercapnia. (L24, Slide 11)

True

False

12.

1 point

Based on West's zones of the lung, which zone is likely to have the highest V/Q ratio? (L24, Slide 20)

Zone I

Zone II

Zone III

Zone IV

13.

1 point

In a patient undergoing a diffusion test, the partial pressure of carbon monoxide in the blood is usually ________ that of the carbon dioxide partial pressure.

less than

equal to

greater than

none of the above

14.

1 point

Peripheral gas exchange is... (L25, Slide 19)

Both Perfusion and Diffusion limited

Diffusion limited

Perfusion limited

Not limited

15.

1 point

Which of the following would not affect O2 uptake along a pulmonary capillary? (L24, Slide 6)

going into a coma

capillary endothelial infection

flying to Denver to go skiing

sprinting 100m

16.

1 point

The "Haldane Effect" describes...
(L25, Slide 24)

the increased affinity of hemoglobin for carbon monoxide and its effect on oxygen release in the periphery

the increased loading of CO2 in the periphery and unloading of CO2 in the lung

the reduction in surface tension created by alveolar surfactant

the reduction in oxygen pressure from the lungs to the alveoli

17.

1 point

In which zone of the lung would you measure left atrial pressure? (L24, Slide 21, verbal)

Zone I

Zone II

Zone III

None of the above

18.

1 point

Which molecule is bound most tightly to hemoglobin? (L25, Slide 16)

CO

HCO3-

CO2

O2

19.

1 point

Carbon dioxide is primarily carried away from peripheral tissues in which form? (L25, Slide 20)

Free gas

Bicarbonate

Dissolved

Carbamino Hemoglobin

20.

1 point

Approximately what percentage of the US population suffers from anatomic shunts causing a decrease in capillary O2 concentration? (L24, Slide 14, verbal)

50%

25%

>99%

17%

21.

1 point

Which form of hemoglobin has the highest affinity for CO2?
(L25, Slide 25)

Oxidized

Reduced

Neutral

All are the same

22.

1 point

If the arterio-venous difference for CO2 in a normal person changed from 4mlCO2/dl to 2 mlCO2/dl, what would be the new normal alveolar oxygen pressure (PAO2)? (L24 & L25, Slide 7, critical equation to memorize)

120 mmHg

50 mmHg

100 mmHg

70 mmHg

23.

1 point

True or false: Oxygen dissolved in the blood is the primary receptor of electrons from the electron transport chain. (L25, Slide 6)

True

False

24.

1 point

A carbonic anhydrase inhibitor would have what affect on PcCO2? (L25, Slide 22)

stay the same

increase

decrease

not enough information

25.

1 point

At approximately how many cm from the bottom of the lung is pulmonary perfusion the highest? (L24, Slide 18)

0 cm

5 cm

10 cm

15 cm

26.

1 point

At standard alveolar oxygen pressure of 100mmHg, the amount of O2 dissolved in the blood is limited by:
(L24, Slide 5)

Diffusion

Perfusion

Both Diffusion and Perfusion

Neither Diffusion nor Perfusion

27.

1 point

Which of the following shunts provide deoxygenated blood to the left ventricle of the heart? (L24, Slide 13)
I: Bronchial circulation
II: Thebesian circulation
III: VSD
IV: ASD

II only

II, III

II, III, IV

III, IV

All of the above

None of the above

28.

1 point

The normal physiological drop in capillary O2 pressure is due to which physiological cause of hypoxemia? (L25, Slide 3)

Diffusion block

Low FiO2

Shunt

Hypoventilation

29.

1 point

Which molecule(s) is/are used to measure diffusion across blood-air barrier?
I: Oxygen
II: Carbon Dioxide
III: Carbon Monoxide
IV: Helium

II & III

I & II

III only

III & IV

II only

I & IV

30.

1 point

A PcCO2 of 60mmHg is indicative of which cause of hypoxemia? (L24, Slide 11)

Physiological Dead Space

Diffusion Abnormality

Low PiO2

Hypoventilation

Shunt

31.

1 point

In which physiological causes of hypoxemia would the A-a gradient remain constant? (L24, Slide 30)
I: V/Q imbalance
II: Low FiO2
III: Shunt
IV: Hypoventilation
V: Diffusion block

I, III

II, III

II, V

III, IV

IV, II IV, II

V only

32.

1 point

What finding is typical of Himalayan sherpas which allows them to function well in a high-altitude environment?

Increased 2,3 DPG

Increased average body temperature

Increased average heart rate

Low blood pH

33.

1 point

Oxygen gas has a molecular weight of 32. CO2 = 44. N2=28. Which has the largest diffusion constant in a liquid? (L24, slide 4)

Oxygen

Carbon dioxide

Nitrogen

Cannot be determined from the data given

34.

1 point

The single ten second breath holding technique is typically used to calculate what? (L24, Slide 7)

Total lung capacity

Alveolar diffusion factor

Capillary partial pressure

Residual volume