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Human Lung

Lungs are part of the human respiratory system. All humans have two lungs which consist of blood capillaries, bronchioles and alveoli. Our lungs are protected by our rib cages which consist of 12 pairs of bones. The breathing process consists of inhalation, which is the process by which our lungs are filled with air, and exhalation, which is the expelling of air from our lungs.

When air is inhaled into the lungs, the following events take place:

• Oxygen in the alveoli will be transferred into our blood capillaries and red blood cell will then transport them to other parts of the body.
• carbon dioxide transferred is transferred from other parts of our bodies to the red blood cells.
• the red blood cells return to the capillaries in the alveoli to release the carbon dioxide and absorb oxygen again.

This is why we breathe in oxygen and breathe out carbon dioxide.

Lung capacity

The term"lung capacity" refers to the amount of air a person lung can hold. The lung capacity of an average person is about 4000 to 6000 cm3. However, only a third of this capacity is normally used. When strenuous work is being done, the body will require more oxygen and the air intake in the lungs will be increased.

Athletes, wind instrument musicians and singers are known to have higher lung capacities compared to a normal person. This does not mean their lungs are bigger. Their chest muscles are stronger allowing them to expand their chests more in order to increase the air intake and to contract the chests more to exhale more air.