Question

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

• A. B : Red blood cell - Mainly transport of ${\mathrm{CO}}_2$
• B. A : Alveolar cavity - Main site of exchange of respiratory gases
• C. D : Capillary wall - Exchange of $O_2$ and ${\mathrm{CO}}_2$ takes place here
• D. C : Arterial capillary - Passes oxygen to tissue

Answer 1

The correct option is B A : Alveolar cavity - Main site of exchange of respiratory gases

Alveolar cavity is a hollow cup shaped structure found in lungs. It is the main site for gaseous exchange.