Questions and Answers
What is the consequence of having high ventilation but low perfusion in the lung?
Increased dead space
Which of the following describes a reason for nonuniform ventilation of the alveoli?
Different metabolic demands in different lung regions
What is the purpose of the shunt equation in understanding pulmonary physiology?
To quantify the amount of blood bypassing the lungs
How does physiologic dead space affect gas exchange in the lungs?
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Which statement accurately summarizes regional differences in ventilation and perfusion?
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How do V/Q ratios relate to gravity in the lungs?
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What influences mixed venous blood to bring CO2 into the lungs and take up alveolar O2?
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Which of the following is a pulmonary vasoconstrictor that increases pulmonary vascular resistance (PVR)?
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What effect does sympathetic innervation have on pulmonary vascular resistance (PVR)?
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Which chemical is known to produce vasodilation in the pulmonary vasculature?
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What intrinsic autoregulation mechanism produces vasoconstriction in the pulmonary vasculature?
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How does parasympathetic innervation affect the pulmonary vasculature?
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What is the impact on the V/Q ratio when the airway is occluded, preventing ventilation?
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What does a shunt in the context of gas exchange refer to?
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How does a pulmonary embolus affect the V/Q ratio?
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What happens if there is matched ventilation and perfusion at the alveolar-capillary unit?
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What is the impact of an intrapulmonary shunt on alveoli?
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How are small shunts typically identified?
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What can cause nonuniform ventilation of the alveoli?
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What is one cause of nonuniform ventilation due to obstruction according to the text?
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How can one assess the distribution of inspired gas in the lungs?
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What may lead to nonuniform compliance in different lung regions?
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What is the physiological shunt equal to?
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What does a pathological right-to-left intracardiac shunt involve?
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What is the equation to calculate venous admixture in the context of shunting?
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Supplemental oxygen will not improve which type of shunt?
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Intrapulmonary shunts are associated with which of the following?
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What does increased arterial-alveolar CO2 difference indicate?
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What is the primary cause of a normal (A-a) DO2?
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Which regions of the lung have high VA/Q ratios?
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Absolute intrapulmonary shunts are also known as 'true shunts' and can be improved with supplemental oxygen.
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Physiological shunt corresponds to anatomic dead space in the lungs.
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Anatomic shunts include venous blood from bronchial, thebesian, and pleural veins entering the left ventricle without passing through pulmonary capillaries.
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Absolute intrapulmonary shunts are associated with well-ventilated alveoli.
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What is the key feature of an anatomic shunt?
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How do absolute intrapulmonary shunts differ from shunt-like states?
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What does the shunt equation conceptually divide all alveolar-capillary units into?
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Which is a pathologic characteristic of the pulmonary vasculature that may contribute to nonuniform ventilation of the alveoli?
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