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KMID : 0383119580060010149
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Journal of Aerospace Medicine
1958 Volume.6 No. 1 p.149 ~ p.155
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LOW OXYGEN TENSION AS A RESPIRATORY STIMULANT
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:Brown, E.B.
저자없음:No authors listed
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Abstract
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The three chemical agents present in the blood that stimulate breaSthing are, C02, H+, and 02. The first 2 stimulate when their concentration is increased and the latter when its concentration is decreased. Carbon dioxide and H+ act at the central respiratory centers in the medulla oblongata and all 3 act at the peripheral chemo-receptors in the carotid and aortic bodies.
Low oxygen is considered a weak respiratory stimulant for two reasons: A considerable fall in oxygen tension must take place before any increase in breathing is measureable, and the maximum increase obtainable from low oxygen. tension is small;rarely more than twofold.
On the other hand Gray has pointed out that low oxygen tension normally acts in the presence of reduced stimulation from CO2 and hydrogen ion, since any Increase in minute volume of respiratory ventilation decreases 002 tension and hydrogen ion concentration of arterial blood. Theoretically then, low oxygen, tension would be a much more potent stimulant for respiration Jif it acted in thy presence of constant CO2 tension and H+ concentration. Figure 1, adapted from Gray, shows the actual increase in ventilation (VR) when Oxygen tension is lowered and CO2 and H+ decrease. In the same figure is shown the theoretical increase when oxygen alone is varied, i. e. when CO2 and H+ are held constant.
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