Question 1

Why is CO the ideal gas for measuring the extent to which the alveolar capillary membrane itself impedes the diffusion rate?

Accepted Answer

A)  Blood can absorb CO at a greater rate than CO can diffuse across the alveolar capillary membrane. 
B)  CO is lighter than O2. 
C)  CO can diffuse across the alveolar capillary membrane faster than blood can absorb it. 
D)  CO is heavier than O2. 
A)  Blood can absorb CO at a greater rate than CO can diffuse across the alveolar capillary membrane. 
B)  CO is lighter than O2. 
C)  CO can diffuse across the alveolar capillary membrane faster than blood can absorb it. 
D)  CO is heavier than O2. A

Question 2

Which of the following laws states that the amount of gas dissolving in a liquid is directly proportional to the gas partial pressure?

Accepted Answer

A)  Boyle's law 
B)  Charles' law 
C)  Henry's law 
D)  Reynold's law 
A)  Boyle's law 
B)  Charles' law 
C)  Henry's law 
D)  Reynold's law C

Question 3

What is the PAOS1U1B12S1U1B0 ofS1U1B0 a person breathing room air at sea level, with a PaCOS1U1B12S1U1B0 equal to 40 mm Hg and an R equal to 0.8?

Accepted Answer

A)  Approximately 80 mm Hg 
B)  Approximately 90 mm Hg 
C)  Approximately 100 mm Hg 
D)  Approximately 110 mm Hg 
A)  Approximately 80 mm Hg 
B)  Approximately 90 mm Hg 
C)  Approximately 100 mm Hg 
D)  Approximately 110 mm Hg C

Question 4

Which of the following conditions can increase the length of the diffusion path?
I.Fibrotic thickening of alveolar and capillary walls
II.Fluid in the alveoli
III.Interstitial edema fluid
IV.Capillary vasoconstriction

Accepted Answer

A)  I, II, III 
B)  II, III 
C)  I, II, III, IV 
D)  II, III, IV 
A)  I, II, III 
B)  II, III 
C)  I, II, III, IV 
D)  II, III, IV

Question 5

Which of the following statements apply to Fick's law?
I.Gas diffusion increases with increased membrane surface area.
II.Gas diffusion increases with decreased membrane surface area.
III.Gas diffusion increases with increased pressure gradient.
IV.Gas diffusion decreases if membrane thickness increases.

Accepted Answer

A)  I, III, IV 
B)  I, II, III, IV 
C)  II, IV 
D)  II, III, IV 
A)  I, III, IV 
B)  I, II, III, IV 
C)  II, IV 
D)  II, III, IV

Question 6

Which of the following are components of the diffusion path?
I.Capillary endothelium
II.Intracellular fluid bathing the hemoglobin molecule
III.Red blood cell membrane
IV.Alveolar epithelium
V.Surfactant layer lining the alveolar surface

Accepted Answer

A)  I, II, III, IV 
B)  II, III 
C)  I, II, III, IV, V 
D)  II, III, IV 
A)  I, II, III, IV 
B)  II, III 
C)  I, II, III, IV, V 
D)  II, III, IV

Question 7

What is the best explanation for the DLO2 being greater than the DLCOsb?

Accepted Answer

A)  O2 is less soluble than CO in the alveolar capillary membrane but more soluble in the plasma and therefore diffuses more rapidly. 
B)  O2 is more soluble than CO in the alveolar capillary membrane and less soluble in the plasma and therefore diffuses more rapidly. 
C)  O2 is less soluble than CO in the alveolar capillary membrane and the plasma and therefore diffuses more rapidly. 
D)  O2 is more soluble than CO in the alveolar capillary membrane and the plasma and therefore diffuses more rapidly. 
A)  O2 is less soluble than CO in the alveolar capillary membrane but more soluble in the plasma and therefore diffuses more rapidly. 
B)  O2 is more soluble than CO in the alveolar capillary membrane and less soluble in the plasma and therefore diffuses more rapidly. 
C)  O2 is less soluble than CO in the alveolar capillary membrane and the plasma and therefore diffuses more rapidly. 
D)  O2 is more soluble than CO in the alveolar capillary membrane and the plasma and therefore diffuses more rapidly.

Question 8

What is the most common cause of resting hypoxemia?

Accepted Answer

A)  A mismatch between ventilation and diffusion 
B)  A mismatch between ventilation and permeability 
C)  A mismatch between ventilation and dead space 
D)  A mismatch between ventilation and blood flow 
A)  A mismatch between ventilation and diffusion 
B)  A mismatch between ventilation and permeability 
C)  A mismatch between ventilation and dead space 
D)  A mismatch between ventilation and blood flow

Question 9

Diffusion of which of the following gases will be limited by a defective alveolar capillary membrane?

Accepted Answer

A)  O2 
B)  CO2 
C)  NO2 
D)  N2O 
A)  O2 
B)  CO2 
C)  NO2 
D)  N2O

Question 10

Which of the following are true of the respiratory exchange ratio?
I.It is the ratio of alveolar CO2 excretion to blood oxygen uptake.
II.R = VCO2/VO2
III.It is the ratio of oxygen uptake to blood alveolar CO2 excretion.
IV.Its value is normally approximately 0.8.

Accepted Answer

A)  I, II, IV 
B)  III, IV 
C)  I, II, III, IV 
D)  II, IV 
A)  I, II, IV 
B)  III, IV 
C)  I, II, III, IV 
D)  II, IV

Question 11

How do you obtain the diffusion capacity for oxygen?

Accepted Answer

A)  It is obtained by multiplying DLCOsb by 1.23. 
B)  It is obtained by multiplying DLCOsb by 24. 
C)  It is obtained by dividing DLCOsb by 1.23. 
D)  It is obtained by dividing DLCOsb by 24. 
A)  It is obtained by multiplying DLCOsb by 1.23. 
B)  It is obtained by multiplying DLCOsb by 24. 
C)  It is obtained by dividing DLCOsb by 1.23. 
D)  It is obtained by dividing DLCOsb by 24.

Question 12

How many times faster does oxygen diffuse through a gas medium than CO2?

Accepted Answer

A)  0.9 
B)  1.0 
C)  1.1 
D)  1.2 
A)  0.9 
B)  1.0 
C)  1.1 
D)  1.2

Question 13

The DLCOsb is useful in differentiating emphysema from what other obstructive disease?

Accepted Answer

A)  Asthma 
B)  Pneumonia 
C)  ARDS 
D)  Bronchiectasis 
A)  Asthma 
B)  Pneumonia 
C)  ARDS 
D)  Bronchiectasis

Question 14

Which of the following is the main limiting factor for the oxygen transfer rate?

Accepted Answer

A)  Perfusion 
B)  Diffusion 
C)  Solubility 
D)  Molecular weight of the gas 
A)  Perfusion 
B)  Diffusion 
C)  Solubility 
D)  Molecular weight of the gas

Question 15

For a person breathing 21% oxygen, what is the inspired oxygen partial pressure?

Accepted Answer

A)  Approximately 80 mm Hg 
B)  Approximately 100 mm Hg 
C)  Approximately 140 mm Hg 
D)  Approximately 160 mm Hg 
A)  Approximately 80 mm Hg 
B)  Approximately 100 mm Hg 
C)  Approximately 140 mm Hg 
D)  Approximately 160 mm Hg

Question 16

Which of the following conditions has an inverse relationship with DLCOsb?

Accepted Answer

A)  Age 
B)  Exercise 
C)  Lung volumes 
D)  PAO2 
A)  Age 
B)  Exercise 
C)  Lung volumes 
D)  PAO2

Question 17

Combining Graham's law and Henry's law, how many times faster does carbon dioxide diffuse across the alveolar capillary membrane than oxygen?

Accepted Answer

A)  10 
B)  20 
C)  30 
D)  40 
A)  10 
B)  20 
C)  30 
D)  40

Question 18

When are patients with thickened alveolar capillary membranes most likely to show evidence of oxygen diffusion impairment?

Accepted Answer

A)  In supine position 
B)  In prone position 
C)  During exercise 
D)  In any position at rest 
A)  In supine position 
B)  In prone position 
C)  During exercise 
D)  In any position at rest

Question 19

Why is N2O the ideal gas for measuring the extent to which pulmonary blood contributes to the diffusion rate?

Accepted Answer

A)  Blood can absorb N2O at a greater rate than N2O can diffuse across the alveolar capillary membrane. 
B)  If N2O is inhaled, the pulmonary capillary blood reaches its maximum capacity for N2O almost instantly. 
C)  If N2O is inhaled, the pulmonary capillary blood reaches its maximum capacity for N2O slowly. 
D)  Blood can absorb N2O at a slower rate than N2O can diffuse across the alveolar capillary membrane. 
A)  Blood can absorb N2O at a greater rate than N2O can diffuse across the alveolar capillary membrane. 
B)  If N2O is inhaled, the pulmonary capillary blood reaches its maximum capacity for N2O almost instantly. 
C)  If N2O is inhaled, the pulmonary capillary blood reaches its maximum capacity for N2O slowly. 
D)  Blood can absorb N2O at a slower rate than N2O can diffuse across the alveolar capillary membrane.

Question 20

The rate of gas diffusion in the lung is inversely proportional to its molecular weight and directly proportional to which of the following physical properties?

Accepted Answer

A)  Density 
B)  Solubility 
C)  Specific gravity 
D)  Proton concentration 
A)  Density 
B)  Solubility 
C)  Specific gravity 
D)  Proton concentration

Exam 7: Gas Diffusion

Why is CO the ideal gas for measuring the extent to which the alveolar capillary membrane itself impedes the diffusion rate?

Which of the following laws states that the amount of gas dissolving in a liquid is directly proportional to the gas partial pressure?

What is the PAO2 of a person breathing room air at sea level, with a PaCO2 equal to 40 mm Hg and an R equal to 0.8?

Which of the following conditions can increase the length of the diffusion path? I.Fibrotic thickening of alveolar and capillary walls II.Fluid in the alveoli III.Interstitial edema fluid IV.Capillary vasoconstriction

Which of the following are components of the diffusion path? I.Capillary endothelium II.Intracellular fluid bathing the hemoglobin molecule III.Red blood cell membrane IV.Alveolar epithelium V.Surfactant layer lining the alveolar surface

What is the best explanation for the DLO2 being greater than the DLCOsb?

What is the most common cause of resting hypoxemia?

Diffusion of which of the following gases will be limited by a defective alveolar capillary membrane?

Which of the following are true of the respiratory exchange ratio? I.It is the ratio of alveolar CO2 excretion to blood oxygen uptake. II.R = VCO2/VO2 III.It is the ratio of oxygen uptake to blood alveolar CO2 excretion. IV.Its value is normally approximately 0.8.

How do you obtain the diffusion capacity for oxygen?

How many times faster does oxygen diffuse through a gas medium than CO2?

The DLCOsb is useful in differentiating emphysema from what other obstructive disease?

Which of the following is the main limiting factor for the oxygen transfer rate?

For a person breathing 21% oxygen, what is the inspired oxygen partial pressure?

Which of the following conditions has an inverse relationship with DLCOsb?

Combining Graham's law and Henry's law, how many times faster does carbon dioxide diffuse across the alveolar capillary membrane than oxygen?

When are patients with thickened alveolar capillary membranes most likely to show evidence of oxygen diffusion impairment?

Why is N2O the ideal gas for measuring the extent to which pulmonary blood contributes to the diffusion rate?

The rate of gas diffusion in the lung is inversely proportional to its molecular weight and directly proportional to which of the following physical properties?

The Airways and Alveoli

The Lungs and Chest Wall

Mechanics of Ventilation

Ventilation

Pulmonary Function Measurements

Pulmonary Blood Flow

Oxygen Equilibrium and Transport

Carbon Dioxide Equilibrium and Transport

Acid-Base Regulation

Control of Ventilation

Ventilation-Perfusion Relationships

Clinical Assessment of Acid-Base and Oxygenation Status

Physiological Basis for Oxygenation and Lung Protection Strategies

Physiology of Sleep Disordered Breathing

Fetal and Newborn Cardiopulmonary Physiology

Functional Anatomy of the Cardiovascular System

Cardiac Electrophysiology

The Electrocardiogram and Cardiac Arrhythmias In Adults

Control of Cardiac Output and Hemodynamic

Filtration, Urine Formation, and Fluid Regulation

Electrolyte and Acid-Base Regulation

Cardiopulmonary Response to Exercise in Health and Disease

Aging and the Cardiopulmonary System

Filters

What is the PAO₂ of a person breathing room air at sea level, with a PaCO₂ equal to 40 mm Hg and an R equal to 0.8?

What is the best explanation for the D_LO₂ being greater than the D_LCO_sb?

Which of the following are true of the respiratory exchange ratio? I.It is the ratio of alveolar CO₂ excretion to blood oxygen uptake. II.R = VCO₂/VO₂ III.It is the ratio of oxygen uptake to blood alveolar CO₂excretion. IV.Its value is normally approximately 0.8.

How many times faster does oxygen diffuse through a gas medium than CO₂?

The D_LCO_sb is useful in differentiating emphysema from what other obstructive disease?

Which of the following conditions has an inverse relationship with D_LCO_sb?

Why is N₂O the ideal gas for measuring the extent to which pulmonary blood contributes to the diffusion rate?