Deck 4: The Diffusion of Pulmonary Gases

Question 1

In the ideal alveolar gas equation,what does 1.25 represent?

A) correction factor for variations in respiratory exchange ratio
B) correction factor for variations in barometric pressure
C) correction factor for variations in water vapor pressure
D) correction factor for variations in FIO₂

Answer 1

A

Question 2

What is the term for the movement of gas molecules from an area of high pressure to an area of low pressure?

A) diffusion
B) osmosis
C) dispersion
D) ventilation

Answer 2

A

Question 3

At sea level,what would the PₐO₂ equal if the PB is 760 mm Hg,the PaCO₂ is 40 mm Hg with FᵢO₂ 1.0?

A) 673 mm Hg
B) 600 mm Hg
C) 573 mm Hg
D) 100 mm Hg

Answer 3

A

Question 4

Which gas law states that the total pressure exterted by a mixture of gases is equal to the sum of the pressures exerted by each gas in the mixture?

A) Dalton's
B) Henry's
C) Graham's
D) Boyle's

Question 5

What is derived from the following equation?
X = [PB -PH₂₀] FIO₂ - PaCO₂ (1.25)

A) PaO₂
B) PaO₂
C) PACO₂
D) PN2

Question 6

What effect does an increased altitude have on the percentage that gases compose in the atmosphere?

A) the percentages remain the same but the partial pressures would decrease with altitude
B) the partical pressures remain the same but the percentages would decrease
C) the percentages and the partial pressures would increase
D) the percentages and the partial pressures would decrease

Question 7

At sea level,what does the PN₂ of the atmosphere equal in mmHg ?

A) 593 mm Hg
B) 760 mm Hg
C) 159 mm Hg
D) 100 mmHg

Question 8

What is absolute humidity of alveolar gas?

A) 44 mg/L
B) 47 mg/L
C) 40 mg/L
D) 21 mg/L

Question 9

What does the PH₂O equal in alveolar gas if the FIO₂ is 0.21?

A) 47 mm Hg
B) 40 mm Hg
C) 100 mm Hg
D) 573 mm Hg

Question 10

What would the partial pressure of oxygen equal if the barometric pressure was 600 mm Hg?

A) 125 mm Hg
B) 159 mm Hg
C) 100 mm Hg
D) 60 mm Hg

Question 11

What accounts for the change in PO₂ between the atmosphere and alveoli?
I)Water vapor pressure in alveolar gas
II)PCO₂ is higher in alveolus than in the atmospheric gas
III)Higher percentage of N₂ in alveolar gas
IV)PB is lower in the alveoli than in the atmosphere

A) I and II only
B) I, II, III, and IV
C) I and IVonly
D) I, II and IV only

Question 12

What percentage of the atmosphere does nitrogen compose?

A) 78%
B) 88%
C) 68%
D) 58%

Question 13

What percentage of the atmosphere does carbon dioxide compose?

A) 0.03%
B) 0.3%
C) 3%
D) 0.003%

Question 14

What is the normal value for the respiratory exchange ratio?

A) 0.8
B) 1.0
C) 0.6
D) 1.25

Question 15

When breathing FIO₂ 1.0 at seal level,what would the PN₂ in the alveoli equal?

A) 0
B) 573 mm Hg
C) 593 mm Hg
D) 47 mm Hg

Question 16

Which gas law is the law of partial pressures?

A) Dalton's law
B) Henry's law
C) Boyle's law
D) Graham's law

Question 17

What is the definition of molecular water?

A) water in the gaseous form
B) water in the liquid form
C) water in the solid form
D) water in either gaseous or liquid form

Question 18

Which gas law is represented by Pᵗᵒᵗᵃˡ= P₁ + P₂ + P₃.... ?

A) Dalton's
B) Boyle's
C) Henry's
D) Charles'

Question 19

What would the partial pressure of oxygen equal in an air mixture at a depth of 99 feet under water?

A) 159 x 4 or 636 mm Hg
B) 159 x 3 or 477 mm Hg
C) 159 x 2 or 318 mm Hg
D) 159 mm Hg

Question 20

When breathing room air,what is the PN₂ in the alveoli?

A) 573 mm Hg
B) 593 mm Hg
C) 700 mm Hg
D) 473 mmHg

Question 21

Under normal resting conditions,what is the total transit time required for blood to move through the alveolar capillary system?

A) 0.75 seconds
B) 0.25 seconds
C) 0.5 seconds
D) 1 second

Question 22

When can the simplified alveolar gas equation be used?
I)PaCO₂ less than 60 mm Hg
II)PaCO₂ greater than 60 mm Hg
III)FIO₂ 0.6 or greater
IV)FIO₂ 0.6 or lower

A) I and III only
B) II and IV only
C) I only
D) II only

Question 23

In a healthy individual at rest,what is the average carbon dioxide tension of venous content blood as it enters the pulmonary capillary?

A) 46 mm Hg
B) 40 mm Hg
C) 35 mm Hg
D) 27 mm Hg

Question 24

In a healthy adult at rest at sea level,what is the normal carbon dioxide gradient across the alveolar capillary membrane?

A) 6 mm Hg
B) 60 mm Hg
C) 40 mm Hg
D) 27 mm Hg

Question 25

In a healthy adult at rest,what duration is required for diffusion of oxygen and carbon dioxide across the alveolary capillary membrane to be complete?

A) 0.25 sec
B) 0.75 sec
C) 0.025 sec
D) 0.075 sec

Question 26

Why is supplemental oxygen indicate when acute alveolar inflammation is superimposed on chronic interstitial lung diseaset?

A) Diffusion is indirectly related to thickness of the a-c membrane and directly related to the pressure gradient (P1-P2) so diffusion will be enhanced with supplemental O₂
B) Diffusion is indirectly related to thickness of the a-c membrane and indirectly related to the pressure gradient (P1-P2) so diffusion will be enhanced with supplemental O₂
C) Diffusion is directly related to thickness of the a-c membrane and directly related to the pressure gradient (P1-P2) so diffusion will be enhanced with supplemental O₂
D) Diffusion is directly related to thickness of the a-c membrane and indirectly related to the pressure gradient (P1-P2) so diffusion will be enhanced with supplemental O₂

Question 27

What are the final three layers (7-8-9)that an oxygen molecule must cross when moving from the alveoli into the blood?

A) plasma of the capillary blood, the erythrocyte membrane, and the intracellular fluid in the erythrocyte.
B) the liquid lining the intra-alveolar membrane, alveolar epithelial cell, and the basement membrane of the alveolar epithelial cell
C) interstitial space, basement membrane of the capillary endothelium, and the intracellular fluid of the erythrocyte
D) the interstitial space, basement membrane of the capillary endothelium, and the capillary endothelium

Question 28

For a healthy adult at rest,what is the normal pressure gradient for oxygen across the alveolar-capillary membrane when breathing room air at sea level?

A) 60 mm Hg
B) 6 mm Hg
C) 40 mm Hg
D) 46 mm Hg

Question 29

Which law is represented by the equation below?
V gas = [AD (P1-P2)] / T

A) Fick's law
B) Dalton's law
C) Henry's law
D) Boyle's law

Question 30

How is oxygen diffusion affected when pulmonary edema is present?

A) Diffusion is indirectly related to thickness of the a-c membrane so diffusion will decrease
B) Diffusion is indirectly related to the thickness of the a-c membrane so diffusion will increase
C) Diffusion is directly related to thickness of the a-c membrane so diffusion will increase
D) Diffusion is directly related to the thickness of the a-c membrane so diffusion will decrease

Question 31

Which of the following are pulmonary effects associated with oxygen toxicity?
I)Tracheobronchitis
II)Substernal chest pain
III)Increased lung compliance
IV)Increased TLC

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

Question 32

What is the solubility of oxygen at 760 mm Hg and 37 ° C?

A) 0.0244 mL/mm Hg/mL H₂O
B) 0.592 mL/mm Hg/ mL H₂O
C) 0.25 mL/mm Hg/mL H₂O
D) 0.75 mL/mm Hg/mL H₂O

Question 33

What is the normal thickness of the alveolar capillary membrane?

A) 0.36 - 2.5 microns
B) 0.36 - 2.5 mm
C) 2.6-3.6 microns
D) 2.6 - 3.5 mm

Question 34

Which of the following are central nervous system effects associated with oxygen toxicity?
I)Tremors
II)Twitching
III)Convulsions
IV)coma

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

Question 35

What are the middle three layers (4-5-6)that an oxygen molecule must cross when moving from the alveoli into the blood?

A) interstitial space, basement membrane of the capillary endothelium, and the capillary endothelium
B) the liquid lining the intra-alveolar membrane, alveolar epithelial cell, and the basement membrane of the alveolar epithelial cell
C) interstitial space, basement membrane of the capillary endothelium, and the intracellular fluid of the erythrocyte
D) plasma of the capillary blood, the erythrocyte membrane, and the intracellular fluid in the erythrocyte.

Question 36

Which of the following pulmonary disorders cause the alveolar-capillary membrane thickness to increase?
I)Pulmonary edema
II)Scleroderma
III)ARDS
IV)Pneumonia

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

Question 37

Which law states that the amount of gas that dissolves in a liquid is directly related to the partial pressure of the gas?

A) Henry's
B) Fick's
C) Dalton's
D) Graham's

Question 38

Which of the following conditions are indications for HBOT?
I)Clostridial gangrene
II)Intracranial abcess
III)Radiation necrosis
IV)Refractory osteomyelitis

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

Question 39

What is the term for the passive movement of gas molecules from a high partial pressure to an area of low partial pressure until equilibrium is reached?

A) diffusion
B) active transport
C) pressure gradient
D) osmosis

Question 40

In order,what are the first three layers of the alveolar capillary membrane that an oxygen molecule crosses?
I)Liquid lining the intra-alveolar membrane
II)Alveolar epithelial cell
III)Basement membrane of the alveolar epithelial cell
IV)Interstitial space

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

Question 41

How do the rates of diffusion of CO₂ and O₂ compare?

A) CO₂ diffuses 20 times faster than O₂
B) O₂ diffuses 20 times faster than CO₂
C) CO₂ diffuses 10 times faster than O₂
D) O₂ diffuses 10 times faster than CO₂

Question 42

What is the term for the situation in which "the rate of gas transfer across the alveolar wall is a function of the amount of blood that flows past the alveoli" ?

A) perfusion limited
B) diffusion limited
C) diffusion
D) penduluft

Question 43

Which law states that the rate of diffusion of a gas through the liquid is directly proportional to the solubility coefficient of the gas and inversely proportional to the square root of the GMW of the gas?

A) Graham's law
B) Henry's law
C) Fick's law
D) Dalton's law

Question 44

What is described by the following: "the movement of gas across the alveolar wall is a function of the integrity of the alveolar-capillary membrane'?

A) diffusion limited
B) diffusion
C) perfusion limited
D) perfusion

Question 45

Which of the following conditions reduce the alveolar surface area?
I)Emphysema
II)Excessive airway secretions
III)Pneumothorax
IV)Sinusitits

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

Question 46

Which of the following is true related to oxygen diffusion?

A) It is normally perfusion limited but under certain abnormal pulmonary conditions can become diffusion limited
B) It is normally diffusion limited but under certain abnormal pulmonary condition can become perfusion limited
C) It can only be diffusion limited
D) It can only be perfusion limited

Question 47

Which gas is used to test the physiologic effectiveness of the alveolary-capillary membrane?

A) CO
B) CO₂
C) O₂
D) N₂O

Question 48

What is the classic diagnostic sign that verifies that a patient has emphysema rather than other types of chronic obstructive disorders?

A) decreased DLCO
B) increased RV
C) increased FRC
D) decreased FEV1

Question 49

What is the normal diffusion capacity of CO?

A) 25 mL/min/mm Hg
B) 20 mL/min/mm Hg
C) 40 mL/min/mmHg
D) 60 mL/min/mmHg