Question

What is the primary gas exchange structure?

Answer 1

Primary gas exchange structure:

1. The primary structure used for the exchange of gases in the lungs is called alveoli.
2. Alveoli are called the structural and functional unit of the lungs.
3. It functions by allowing the movement of oxygen and carbon dioxide through diffusion between the lungs and bloodstream.
4. There are more than 480 alveoli in each human lung.

Process of gas exchange:

1. Inhaled oxygen enters the lungs and reaches the alveoli.
2. The layers of cells lining the alveoli and the surrounding capillaries are only one cell thick and in close contact with each other.
3. This barrier between air and blood averages about 1 micron in thickness.
4. Oxygen passes quickly through this air-blood barrier into the blood in the capillaries through diffusion.
5. Similarly, carbon dioxide passes from the blood into the alveoli and is then exhaled.