BRS REVIEW PHYSIOLOGY EXAM QUESTIONS AND ANSWERS
WITH COMPLETE SOLUTIONS VERIFIED
Which of the following lung volumes or capacities can be measured by
spirometry?
A. Functional Residual Capacity (FRC)
B. Physiological dead space
C. Total Lung Capacity (TLC)
E. Vital Capacity (VC)
The answer is E
Residual volume (RV) cannot be measured by spirometry. Therefore, any lung volume
or capacity that includes the RV cannot be measured by spirometry. Measurements that
include RV are functional residual capacity (FRC) and total lung capacity (TLC). Vital
capacity does not include RV and is not measureable by spirometry and requires
sampling of arterial PCO2 and expired CO2..
An infant born prematurely in gestational week 25 has neonatal respiratory
distress syndrome. Which of the following would be expected in this infant?
A. Arterial PO2 of 100 mmHg
B. Collapse of the small alveoli
,C. Increased lung compliance
D, Normal Breathing rate
E. lecithin: sphingomyelin ratio of > 2:1 in amniotic fluid
The answer is B.
Neonatal respiratory distress.syndrome is caused by lack of adequate surfactant in the
immature lung. Surfactant appears between the 24th and 35th gestational week. In the
absence of surfactant, the surface tension of the small alveoli is too high (P= 2T/r), the
small alveoli collapse into larger alveoli; and ventilation/perfusion (V/Q) mismatch,
hypoxemia and cyanosis occurs. The lack of surfactant also decreases lung
compliance, making it harder to inflate the lungs, increasing the work of breathing and
producing dyspnea (shortness of breath). Generally, lecithin: sphingomyelin rations
greater than 2:1 signify mature levels of surfactant.
In which vascular bed does hypoxia cause vasoconstriction?
A. Coronary
B. Pulmonary
C. Cerebral
D. Muscle
E. Skin
Answer B:
Pulmonary blood flow is controlled locally by the PO2 of alveolar air. Hypoxia causes
pulmonary vasoconstriction and thereby shunts blood away from unventilated areas of
, the lungs, where it would be wasted, in the coronary circulation, hypoxemia causes
vasodilation., The cerebral muscle and skin circulations are not directly controlled by
PO2.
A 12 year old child has a severe asthmatic attack with wheezing. The child
experiences rapid breathing and becomes cyanotic. The arterial PO2 is 60 mmHg
and the PCO2 is 30 mmHg.
Which of the following is most true?
A. Forced expiratory volume1/Forced vital capacity (FEV1/FVC) is increased.
B. Ventilation/perfusion (V/Q) ratio is increased in the affected areas of his lungs.
C. His arterial PCO2 is higher than normal because of inadequate gas exchange
D. His arterial PCO2 is lower than normal
The answer is D
The patient's arterial Pco2 Is lower than the normal value of 40 mmHg because
hypoxemia has stimulated peripheral chemoreceptors to increase his breathing rate;
hyperventilation causes the patient to blow off extra CO2 and results in respiratory
alkalosis. In an obstructive disease such as asthma, both forced respiratory volume
(FEV1) and forced vital capacity (FVC) are decreased, with the larger decrease
occurring in FEV1. Therefore, the FEV1/FVC ratio is decreased. Poor ventilation of the
affected areas decreases the ventilation/perfusion (V/Q) RATIO and causes hypoxemia.
The patient's residual volume RV is increased because he breathing at a higher lung
volume.
5. To treat this patient
WITH COMPLETE SOLUTIONS VERIFIED
Which of the following lung volumes or capacities can be measured by
spirometry?
A. Functional Residual Capacity (FRC)
B. Physiological dead space
C. Total Lung Capacity (TLC)
E. Vital Capacity (VC)
The answer is E
Residual volume (RV) cannot be measured by spirometry. Therefore, any lung volume
or capacity that includes the RV cannot be measured by spirometry. Measurements that
include RV are functional residual capacity (FRC) and total lung capacity (TLC). Vital
capacity does not include RV and is not measureable by spirometry and requires
sampling of arterial PCO2 and expired CO2..
An infant born prematurely in gestational week 25 has neonatal respiratory
distress syndrome. Which of the following would be expected in this infant?
A. Arterial PO2 of 100 mmHg
B. Collapse of the small alveoli
,C. Increased lung compliance
D, Normal Breathing rate
E. lecithin: sphingomyelin ratio of > 2:1 in amniotic fluid
The answer is B.
Neonatal respiratory distress.syndrome is caused by lack of adequate surfactant in the
immature lung. Surfactant appears between the 24th and 35th gestational week. In the
absence of surfactant, the surface tension of the small alveoli is too high (P= 2T/r), the
small alveoli collapse into larger alveoli; and ventilation/perfusion (V/Q) mismatch,
hypoxemia and cyanosis occurs. The lack of surfactant also decreases lung
compliance, making it harder to inflate the lungs, increasing the work of breathing and
producing dyspnea (shortness of breath). Generally, lecithin: sphingomyelin rations
greater than 2:1 signify mature levels of surfactant.
In which vascular bed does hypoxia cause vasoconstriction?
A. Coronary
B. Pulmonary
C. Cerebral
D. Muscle
E. Skin
Answer B:
Pulmonary blood flow is controlled locally by the PO2 of alveolar air. Hypoxia causes
pulmonary vasoconstriction and thereby shunts blood away from unventilated areas of
, the lungs, where it would be wasted, in the coronary circulation, hypoxemia causes
vasodilation., The cerebral muscle and skin circulations are not directly controlled by
PO2.
A 12 year old child has a severe asthmatic attack with wheezing. The child
experiences rapid breathing and becomes cyanotic. The arterial PO2 is 60 mmHg
and the PCO2 is 30 mmHg.
Which of the following is most true?
A. Forced expiratory volume1/Forced vital capacity (FEV1/FVC) is increased.
B. Ventilation/perfusion (V/Q) ratio is increased in the affected areas of his lungs.
C. His arterial PCO2 is higher than normal because of inadequate gas exchange
D. His arterial PCO2 is lower than normal
The answer is D
The patient's arterial Pco2 Is lower than the normal value of 40 mmHg because
hypoxemia has stimulated peripheral chemoreceptors to increase his breathing rate;
hyperventilation causes the patient to blow off extra CO2 and results in respiratory
alkalosis. In an obstructive disease such as asthma, both forced respiratory volume
(FEV1) and forced vital capacity (FVC) are decreased, with the larger decrease
occurring in FEV1. Therefore, the FEV1/FVC ratio is decreased. Poor ventilation of the
affected areas decreases the ventilation/perfusion (V/Q) RATIO and causes hypoxemia.
The patient's residual volume RV is increased because he breathing at a higher lung
volume.
5. To treat this patient
