8) Ventilation–perfusion inequalities lead to hypoxemia becausea) the relationship between PCO2 and the content of CO2 in blood is sigmoidal.b) a decrease in ventilation–perfusion matching in a lung region causes pulmonaryarteriolar vasodilation in that region.c) increases in ventilation cannot fully restore O2 content in areas with lowventilation–perfusion matching.d) increases in ventilation cannot normalize PCO2.e) pulmonary blood vessels are not sensitive to changes in PO2
Question
- Ventilation–perfusion inequalities lead to hypoxemia becausea) the relationship between PCO2 and the content of CO2 in blood is sigmoidal.b) a decrease in ventilation–perfusion matching in a lung region causes pulmonaryarteriolar vasodilation in that region.c) increases in ventilation cannot fully restore O2 content in areas with lowventilation–perfusion matching.d) increases in ventilation cannot normalize PCO2.e) pulmonary blood vessels are not sensitive to changes in PO2
Solution
Ventilation-perfusion inequalities lead to hypoxemia because of the following reason:
c) Increases in ventilation cannot fully restore O2 content in areas with low ventilation-perfusion matching.
In a healthy lung, there is a balance between the amount of air reaching the alveoli (ventilation) and the amount of blood flow in the capillaries around the alveoli (perfusion). This is known as ventilation-perfusion matching. When this balance is disrupted, it can lead to areas of the lung that are either underventilated (low ventilation-perfusion ratio) or overventilated (high ventilation-perfusion ratio).
In areas of the lung with low ventilation-perfusion matching, there is not enough air reaching the alveoli to fully oxygenate the blood flowing past. Even if ventilation is increased, it may not be enough to fully restore the oxygen content of the blood in these areas, leading to hypoxemia (low blood oxygen levels).
Similar Questions
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a decrease in ventilation–perfusion matching in a lung region causes pulmonaryarteriolar vasodilation in that region.
In a healthy person, the partial pressure of carbon dioxide (pCO2) in systemic arterial blood is equal to the pCO2 in the alveoli.
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