The exchange of oxygen and carbon dioxide between alveolar air and blood occurs mainly by

Options

  • A. Active transport
  • B. Diffusion
  • C. Osmosis
  • D. Filtration
  • E. Endocytosis

Correct Answer (Detailed Explanation is Below)

B. Diffusion

Detailed Explanation

Oxygen and carbon dioxide cross the respiratory membrane primarily by diffusion down their respective partial-pressure gradients.