Blood : a study in general physiology / by Lawrence J. Henderson.

  • Lawrence Joseph Henderson
Date:
1928
Catalogue details

Licence: In copyright

Credit: Blood : a study in general physiology / by Lawrence J. Henderson. Source: Wellcome Collection.

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    crease in r and relative acidity of serum, increasing oxy¬ gen pressure causes a decrease in (HC03)c and no direct change in (HC03~)s, hence a decrease in r and relative acidity of cells. Therefore, increase of pressure of carbon dioxide is accompanied by a movement of chloride ions into the cells, increase of oxygen pressure by a movement of chloride ions out of the cells. In short, the older theory is consistent with the facts and with the more recent theory as quantitatively developed by Van Slyke87 from the Gibbs-Donnan law\ But the older theory cannot of course explain the quantitative relations because it was put forth at a time when the magnitude of the differences in concentrations between cells and serums was unknown and theoretically inexplicable. The older theory takes ac¬ count of the known increases or decreases of unknown differences between concentrations in cells and plasma, the theory of Van Slyke, Wu, and McLean of known values and ratios of these concentrations. We may now proceed to a more detailed consideration of the magnitudes of the changes involved in changing the partial pressure of carbon dioxide. Here, again, we shall follow Van Slyke.88 In figure 20, A approximately represents the composition of oxygenated human blood when the value of pHs is 7.8. The conditions are those de¬ fined by equations 3, 4, 5, and 6. In other words, ionic neutrality exists in cells and in serum, osmotic equilib¬ rium exists between cells and serum, and the values of r for chloride and bicarbonate ions are equal. B represents the changes in the cells following increase of the pressure of carbon dioxide to the value where pHc becomes 6.6— the isoelectric point of oxyhemoglobin. Now all the base which was bound by hemoglobin has become bicarbonate, 87 Van Slyke, Wu, and McLean, Journal of Biological Chemistry, LYI, 765 (1923). 88 D. D. Van Slyke, Factors Affecting the Distribution of Electro¬ lytes, Water, and Gases in the Animal Body, pp. 18-20, Philadelphia and London, 1926.
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