Question

The figure given shows a small part of human lung where exchange of gases takes place. In which one of the options given, the one part A, B, C or D is correctly identified along with its function.

• A. B: Red blood cell- transport of $C{O}_2$ mainly
• B. C: Arterial capillary-passes oxygen to tissues
• C. A: Alveolar cavity - main site of exchange of respiratory gases
• D. D: Capillary wall - exchange of $O_2$ and $C{O}_2$ takes place here

Answer 1

Answer: (C)

A: Alveolar cavity - main site of exchange of respiratory gases

Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. Inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.

So, option C is the correct option.