The figure given below shows a small part of human lung where exchange of gas takes place. In which one of…
The figure given below shows a small part of human lung where exchange of gas 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 - Alveolar cavity - main site of exchange of respiratory gases
D - Capillary wall - exchange of and takes place here
B - Red blood cell - transport of mainly
C - Arterial capillary - passes oxygen to tissues
Solution
Alveoli are the primary sites of exchange of gases. The exchange of gases $\left(\mathrm{O}_2\right.$ and $\left.\mathrm{CO}_2\right)$ between the alveoli and the blood occurs by simple diffusion.
