| 2.2 |
The Movement and Exchange of Gases in The Human Body |
| Definition |
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Oxygen and carbon dioxide gas exchange occurs in the alveoli in the lungs and is transported using red blood cells to all cells of the body
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The process of gas exchange in the alveoli and cells of the body:
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The high oxygen content in the alveoli causes the process of oxygen diffusion into the blood capillaries to occur
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In the blood capillaries, oxygen combines with hemoglobin to form oxyhaemoglobin
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The oxyhaemoglobin is transported using red blood cells to all cells of the body and oxygen is released
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In the cells of the body, the process of oxidation (cellular respiration) takes place to produce energy and carbon dioxide
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The carbon dioxide permeates from the cells into the capillary tissue and is subsequently transported to the lungs for elimination
The adaptation of alveolar structure to maximize gas exchange:
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A large surface area for gas exchange in the alveoli can increase the oxygen content
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The surface of the alveoli is moist so that gas easily permeates out and into the alveoli
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The alveoli are thin-walled as thick as one cell to facilitate gas prescription
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The alveoli are surrounded by a network of blood capillaries to facilitate rapid gas transport
