Question

What will be the pO₂ and pCO₂ in the atmospheric air compared to those in the alveolar air?

Options

• pO₂ lesser, pCO₂ higher

• pO₂ higher, pCO₂ lesser

• pO₂ higher, pCO₂ higher

• pO₂ lesser, pCO₂ lesser

Answer 1

pO₂ higher, pCO₂ lesser

Explanation:

• The partial pressure of oxygen in atmospheric air is higher than that of oxygen in alveolar air.
• In atmospheric air, pO₂ is about 159 mm Hg. In alveolar air, it is about 104 mm Hg.
• The partial pressure of carbon dioxide in atmospheric air is less than that of carbon dioxide in alveolar air. In atmospheric air, pCO₂ is about 0.3 mmHg. In alveolar air, it is about 40 mm Hg.