Question

What is the approximate normal composition of alveolar air?

• A. 14% oxygen, 6% carbon dioxide, 80% nitrogen
• B. 21 % oxygen, 2% carbon dioxide, 77% nitrogen
• C. 16% oxygen, 3% carbon dioxide, 81 % nitrogen
• D. 10% oxygen, 8% carbon dioxide, 82% nitrogen

Answer 1

Answer: (A)

14% oxygen, 6% carbon dioxide, 80% nitrogen

The air present inside the alveoli or the alveolar air usually has a higher amount of oxygen than carbon dioxide. The approximate composition of alveolar air under normal condition is 14% oxygen, 6% carbon dioxide, and 80% nitrogen.

So, the correct answer is '14% oxygen, 6% carbon dioxide, 80% nitrogen'.