Term
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Definition
| Produced from cell metabolism. About 65% carried inside RBC's. About 30% combines with hemoglobin. About 5% transported in solution in plasma. |
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Term
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Definition
As cells consume O² partial pressure in tissue drops, causing O² at arterial end of the capillary to diffuse into cells. When cells consume more O², stress/excerise, the pressure gradient & diffuse are enhanced. |
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Term
Systemtic Diffusion
(CO²) |
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Definition
CO² from metabolic processes accumulates in tissues & diffuses into capillaries where partial pressure is lower. |
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Term
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Definition
| Healthy bodies are driven to breathe by high CO² levels not low O² levels. |
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Term
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Definition
| A chemosensitive center in the medulla oblongata is highly responsive to high CO² in the blood. This center influences other respiratory centers & increases activity of respirations, rate & depth. Also nueral receptors outside the CNS in the carotid bodies & aortic bodies above & below the aortic arch are sensitive to a decrease in O². |
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Term
Factors causing O² to be main drive to breathe
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Definition
| Some chronic lung ailments such as emphysema, cause low O² to be the main drive to breathe. Here chronically high CO² "desensities" the chemoreceptors. Sometimes called the hypoxic drive. So increasing the O² concentration depresses breathing. O² must be administered with caution. |
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