Indicate the best answer or completion.
2. A child with normal lung volumes for his age (TLC = 2.5 liters, VC = 2.0 liters, ERV = 0.5 liters) would expected to have an FEV1 (one-second forced expired volume) in the range of
A. 0.5-1.0 liters
B. 1.0-1.6 liters
C. 1.6-2.0 liters
D. 2.0-2.5 liters
E. 2.5-3.0 liters
3. Contraction of the abdominal muscles is important in
A. normal (quiet) inspiration
B. forced (maximum) inspiration
C. normal (quiet) expiration
D. forced (maximum) expiration
E. none of the above
4. Alveolar surfactant acts to increase pulmonary
A. surface tension
B. compliance
C. airway resistance
D. blood flow
E. both B and D above
5. Administration of an agonist for which of the following autonomic receptors would be expected to cause airway resistance to decrease?
A. muscarinic-cholinergic
B. nicotinic-cholinergic
C. alpha-adrenergic
D. beta-adrenergic
E. histaminic
6. In emphysema, which of the following would be expected to be below normal (less positive or more negative than normal)?
A. airway resistance
B. lung compliance
C. intrapleural pressure
D. FEV1
E. B, C, and D above
7. At which of the following times in the respiratory cycle is the intrapleural pressure most negative?
A. just after the beginning of inhalation (inspiration
B. just before the end of inhalation
C. just after the beginning of exhalation (expiration)
D. just before the end of exhalation
E. any of the above, since the intrapleural pressure is constant during the normal respiratory cycle
The following questions refer to measurements taken on a male subject, age 25, at rest. Indicate whether the value given for a particular measurement is above the value that would be expected for a normal subject, below normal, or contained within the normal range.
8. Residual volume of 2.5 liters
A. above normal
B. below normal
C. within the normal range
9. Intrapleural pressure with relaxed respiratory muscles of -5 cmH2O
A. above normal (less negative than normal)
B. below normal (more negative than normal)
C. within the normal range
10. PEF (peak expired flow rate) of 250 liters/minute
A. above normal (less negative than normal)
B. below normal (more negative than normal)
C. within the normal range
PRACTICE EXAMINAITON QUESTIONS: Alveolar Gas Exchange
1. What would be the expected effect of pulmonary edema on the pulmonary diffusing capacity for oxygen (DO2) and carbon dioxide (DCO2)
A. reduce DO2 and reduce DCO2
B. reduce DO2 but no effect on DCO2
C. reduce DCO2 but no effect on DO2
D. no effect on either DO2 or DCO2
E. no effect on either DO2 or DCO2 unless diffusing area is reduced also
2. At which of the following sites is the partial pressure of carbon dioxide (PCO2) highest?
A. exhaled gas
B. alveolar gas
C. systemic arterial blood
D. systemic venous blood
E. about the same in all of the above (40 mmHg)
3. At which of the following sites is the partial pressure of oxygen (PO2) highest?
A. exhaled gas
B. anatomical dead space at the end of expiration
C. anatomical dead space at the end of inspiration
D. alveolar gas
E. about the same in all of the above (100 mmHg)
4. An individual who breaths through a hose or tube while keeping his baseline tidal volume and breathing frequency unchangedl would be expected to have an increased (compared to normal) of which of the following?
A. dead space
B. wasted ventilation
C. systemic arterial carbon dioxide content (Ca-CO2)
D. all of the above
E. only A and B above
5. At the top of a 3000 meter high mountain, which of the following alveolar partial pressures would be expected to be lower than normal? (Remember that barometric pressure, PB, decreases as one goes higher.)
A. oxygen (PA-O2)
B. carbon dioxide (PA-CO2)
C. water vapor (PA-H2O)
D. all of the above
E. only A and B above
6. Reduction of the pulmonary diffusing capacity to one-fourth of its normal value would be expected to have what effect on systemic arterial oxygen and carbon dioxide partial pressures (compared to normal)?
A. decrease Pa-O2 and decrease Pa-CO2
B. decrease Pa-O2 and increase Pa-CO2
C. increase Pa-O2 and decrease Pa-CO2
D. increase Pa-O2 and increase Pa-CO2
E. decrease Pa-O2 but no change in Pa-CO2
7. At rest, wasted ventilation as a percent of total ventilation of 30% is
A. above normal
B. below normal
C. within the normal range
PRACTICE EXAMINAITON QUESTIONS - BLOOD GAS TRANSPORT
1. Cyanosis (a bluish color of the skin and mucous membranes) indicates a higher than normal blood concentration of
A. carbon dioxide
B. carbon monoxide
C. hydrogen ion
D. diphosphogycerate (DPG)
E. reduced hemoglobin
2. As blood passes through systemic capillaries, what happens to the affinity of hemoglobin for oxygen and what happens to the Hb-O2 dissociation curve?
A. Hb affinity for O2 increases and the dissociation curves shifts to the left
B. Hb affinity for O2 increases and the dissociation curves shifts to the right
C. Hb affinity for O2 decreases and the dissociation curves shifts to the left
D. Hb affinity for O2 decreases and the dissociation curves shifts to the right
E. neither Hb affinity for O2 nor the Hb-O2 dissociation curve change
3. Suppose a person has a genetic defect causing him to continue to produce fetal hemoglobin (rather than normal hemoglobin) throughout adult life. What would be the expected systemic arterial oxygen partial pressure and saturation (compared to a normal person)?
A. higher Pa-O2 and higher Hb O2 saturation
B. higher Pa-O2 but lower Hb O2 saturation
C. lower Pa-O2 but higher Hb O2 saturation
D. lower Pa-O2 and lower Hb O2 saturation
E. normal Pa-O2 but higher Hb O2 saturation
4. Compared with systemic arterial blood, pulmonary arterial blood has a higher
A. oxygen content
B. pH
C. bicarbonate ion concentration
D. Hb concentration
E. none of the above
5. As blood passes through systemic capillaries, the enzyme carbonic anhydrase catalyzes
A. conversion of dissolved CO2 to carbonic acid
B. conversion of carbonic acid to bicarbonate ion
C. conversion of gaseous CO2 to dissolved CO2
D. binding of carbon dioxide to hemoglobin, thus displacing oxygen
E. all of the above
6. What would be the expected systemic arterial oxygen content of a normal person inhaling pure oxygen (100% O2) for an hour or so?
A. 100 ml O2 / dl blood (100 ml blood)
B. 40 ml O2 / dl blood (100 ml blood)
C. 22 ml O2 / dl blood (100 ml blood)
D. 11 ml O2 / dl blood (100 ml blood)
E. none of the above, since pure oxygen is toxic and would cause death within the hour
7. An oxyhemoglobin saturation of mixed systemic venous blood of 25% for a person at rest is
A. above normal
B. below normal
C. within the normal range
8. A hemoglobin concentration in systemic venous blood of 20 gm/dl blood is
A. above normal
B. below normal
C. within the normal range
PRACTICE EXAMINAITON QUESTIONS - PULMONARY CIRCULATION
Indicate the best answer or completion.
1. When is the resistance to blood flow of the pulmonary vascular bed lowest?
A. When a person is at rest sitting up
B, When a person is at rest lying down
C. When a person is breathing air at high altitude
D. When a person is exercising maximally
E. None of the above because pulmonary vascular resistance is constant
2. Which of the following might be expected to lead to pulmonary edema?
A. decrease pulmonary arterial pressure (pulmonary hypotension)
B. decrease in systemic arterial pressure (systemic hypotension)
C. decrease volume of blood in the pulmonary circulation (as in hemorrhage)
D. increase systemic venous pressure (as in right heart failure)
E. increase pulmonary capillary permeability to plasma proteins (as in pulmonary inflammation)
3. In a person standing upright, which region of the lungs has the highest ventilation rate and which region has the highest circulatory perfusion rate?
A. highest ventilation: Apex; highest perfusion: Apex
B. highest ventilation: Apex; highest perfusion: Base
C. highest ventilation: Base; highest perfusion: Apex
D. highest ventilation: Base; highest perfusion: Base
E. there is no "highest" region as the apex and base have equal ventilation and perfusion rates
PRACTICE EXAMINAITON QUESTIONS - ALVEOLAR-ARTERIAL EQUILIBRATION
1. Which of the following represents a "right-to-left shunt"?
A. pulmonary blood flow through a region of lung atelectasis (alveolar collapse
B. blood flow from the left ventricle to the right ventricle through a hole in the interventricular septum
C. blood flow from skin arteries to skin veins which does not pass through skin capillaries
D. blood flow from the aorta into the pulmonary artery through the ductus arteriosis
E. all of the above
2. A patient has an alveolar PA-O2 of 60 mmHg and a systemic arterial Pa-O2 of 56 mmHg. The most likely explanation for these values is
A. hypoventilation
B. diffusion limitation
C. right-to-left shunt
D. ventilation-to-perfusion nonuniformity
E. either B, C, or D above
3. All of the following are possible causes of a higher than normal AaDO2 except
A. pulmonary edema
B. mismatching of alveolar ventilation and pulmonary perfusion
C. hypoventilation
D. a cardiac septal defect that allows blood to flow from the right atrium to the left atrium
E. none of the above; that is, none are exceptions, since all could lead to a high AaDO2
4. Lack of oxygen equilibration due to diffusion limitation ("alveolar-capillary block") can be evaluated by measuring the
A. distribution of an inhaled gas mixture containing a radioactive marker
B. diffusing capacity of CO (carbon monoxide)
C. diffusing capacity of CO2 (carbon dioxide)
D. diffusing capacity of N2 (nitrogen) when inhaling air
E. FEV-1/VC when inhaling pure oxygen
5. Blood gas measurements in an hypoxic patient indicates that the patient’s systemic arterial oxygen content is normal but his systemic venous oxygen content is low. This is characteristic of
A. diffusion limitation
B. right-to-left shunt
C. pulmonary ventilation/perfusion nonuniformity
D. anemic hypoxia (low Hb concentration)
E. stagnant hypoxia (low cardiac output)
6. A patient has a normal oxygen partial pressure and content in pulmonary venous blood but his systemic arterial blood shows a significantly lower than normal oxygen partial pressure and content. This is diagnostic of
A. diffusion limitation
B. right-to-left shunt
C. pulmonary ventilation/perfusion nonuniformity
D. stagnant hypoxia (low cardiac output)
E. A, B. or C above
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