Question

If the partial pressures of oxygen and carbon dioxide in the alveoli are 104 and 40 and in the blood reaching the alveoli at that moment it is 40 and 45 respectively, then oxygen and carbon dioxide will diffuse from

• A. Both oxygen and carbon dioxide will diffuse from blood into alveoli
• B. Oxygen will diffuse from blood into alveoli and carbon dioxide will diffuse from alveoli into blood
• C. Oxygen will diffuse from alveoli into blood and carbon dioxide will diffuse from blood into alveoli
• D. There will be no exchange of gases

Answer 1

The correct option is C

Oxygen will diffuse from alveoli into blood and carbon dioxide will diffuse from blood into alveoli

The partial pressure of oxygen is higher in the alveoli and lower in the blood. The partial pressure of carbon dioxide is higher in the blood and lower in the alveoli. So, oxygen will diffuse from alveoli into blood and carbon dioxide will diffuse from blood into alveoli.