Zoology - Breathing and Exchange of Gases Question with Solution | TestHub

Alveoli are the structural and functional unit of the lungs. They are tiny sacs which helps in the gaseous exchange while breathing by the process of diffusion. Alveoli cells are made of simple epithelial tissue. Alveoli become less efficient because of disease, normal aging, smoking and air pollution. If the gas is more soluble or has higher partial pressure gradient, the transport of gases will be at a faster rate. However, if the thickness of the respiratory membrane increases the diffusion of gases across it will decrease.