In the lung's alveoli, there are four gases mixed together: oxygen, carbon dioxide, nitrogen, and water vapor. At a normal barometric pressure of 760 mm Hg, alveolar O₂ exerts a partial pressure of 100 mm Hg, CO₂ 40 mm Hg, and water vapor 47 mm Hg. What is the alveolar partial pressure of nitrogen?

Question

Quizplus · Accepted Answer

The total pressure in the alveoli is the sum of the partial pressures of all gases present. Subtracting the partial pressures of oxygen (100 mm Hg), carbon dioxide (40 mm Hg), and water vapor (47 mm Hg) from the total barometric pressure (760 mm Hg) gives the partial pressure of nitrogen: 760 - 100 - 40 - 47 = 573 mm Hg.

In the Lung's Alveoli, There Are Four Gases Mixed Together