Respiratory System Questions and Answers PDF Related

Review Respiratory System Questions and Answers PDF related questions and content

Oxygen and carbon dioxide concentration in the alveolar air is respectively

  • A. 16 % and 4%
  • B. 19.8 % and 4.6 %
  • C. 21 % and 4%
  • D. 13.1 % and 5 %
Correct Answer: D

Rationale: The correct answer is D (13.1% oxygen and 5% carbon dioxide). In the alveolar air, the oxygen concentration is around 13.1%, which is lower than atmospheric air (21%) due to gas exchange in the lungs. The carbon dioxide concentration in alveolar air is around 5%, higher than atmospheric air (0.04%). Choices A, B, and C have oxygen concentrations higher than what is found in alveolar air, making them incorrect. Choice B also has a carbon dioxide concentration higher than what is typically found in alveolar air, making it incorrect.