Amount of oxygen in inspired air is 21% while in expired air is:
Correct answer: D. 16%
- A. 11%
- B. 12%
- C. 15%
- D. 16%
Explanation
The amount gases in exhaled air are 4% to 5% by volume more carbon dioxide and 4% to 5% by volume less oxygen than was inhaled. This expired air typically composed of: 78.04% nitrogen; 13.6% - 16% oxygen; 4% - 5.3% carbon dioxide; 1% other gases.
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About Respiration
The human respiratory system includes the air passages, lungs, alveoli and breathing muscles, while gaseous exchange explains how oxygen enters blood and carbon dioxide leaves it by diffusion. The effects of smoking include damage to cilia and alveoli, reduced gas exchange, chronic bronchitis, emphysema and increased risk of lung cancer.
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