Question

Describe the mechanism of respiration in man.

Answer 1

Mechanism of respiration:

1. In humans, respiration takes place in two phases, i.e. inspiration and expiration.
2. The process of inhaling air into the lungs is an inspiration.
3. At the time of inspiration, the contraction of diaphragm muscles takes place and the diaphragm moves downward.
4. This leads to an increase in the volume of the chest cavity and the pressure of air within the chest cavity reduces.
5. The oxygenated air present external to the body is at a high-pressure flow briskly into the lungs.
6. The oxygenated air in the lungs reaches the alveoli.
7. The passing of oxygen takes place via the walls of the alveoli into the blood found in the blood capillaries.
8. The oxygen is then innervated to all the body tissues.
9. From the tissues, the waste components like carbon dioxide are captivated by the blood and are carried to the lungs' alveoli for expiration.
10. The process of exhaling air from the lungs is expiration.
11. At the time of expiration, the diaphragm muscles relax and the diaphragm moves upward.
12. This leads to a decline in the chest cavity volume.
13. The air pressure within the chest cavity enhances, which pushes the carbon dioxide out from the body.