describe the mechanism of breathing in human beings....
The organs of the respiratory system extend from the nose to lungs. They include the nose, pharynx, trachea, bronchi, and bronchioles. The intake of O2 and exit of CO2 called breathing which involves two processes:
Breathing involves two processes
1) Inhalation: It involves bringing in air from outside the body into the lungs. When we breathe in, the size of our chest increases.This happens because when air enters, the lungs expand and the ribs move outwards. Simultaneously, the diaphragm contracts and becomes flat. Thus, the size of our chest increases.
2) Exhalation: It involves removal of CO2 from the body. When we breathe out, the size of our chest decreases. This happens because when air moves out of our lungs, the lungs contract, the ribs move back, and the diaphragm curves upwards into the chest decreasing the size of the chest.
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