342 RESPIRATORY FUNCTION OF THE BLOOD 



consequent adjustment of r, vol and pH^ to meet the new con- 

 ditions. Thus, by this simple diagram, the complicated changes 

 occurring in the blood during respiration or following on the 

 activity of any organ, can be depicted. 



It must be noted that each alignment chart represents the 

 conditions in the sample of blood from the analysis of which it was 

 constructed, and must not be applied generally to any blood under 

 any conditions. Any change of condition necessitates the con- 

 struction of a new chart. 



Integrative action of blood plasma. 



Plasma must be considered as a solution of water in colloid 

 separated from other fluids (with which it is in equilibrium) by 

 membranes permeable to certain solutes. The whole transport 

 system is a multi-phase colloidal complex in equilibrium. Altera- 

 tions in any phase produce regulatory changes in every other phase. 

 Briefly, blood has an integrative action. 



To come back to the simile of a community : suppose Cotton- 

 opolis failed to function normally. This would be manifested by the 

 scarcity of cotton goods in the hands of the distributors. The 

 cause of the failure might be found by a process of elimination. 

 In general, (1) either the supply of raw material was inadequate 

 (bad harvest or transport strike), (2) or the supply of fuel was 

 restricted (coal strike), (3) or the workers were on strike, or (4) the 

 means of distributing the finished product had broken down 

 (transport strike). It might even happen that (5) over-production 

 had " drugged " the market, producing the invariable reaction on 

 the factory. Similar mishaps might overtake that collection of 

 cell-communities called the animal organism. (1) If the various 

 raw materials are not available even when ample fuel supplies 

 exist, cell life becomes narrowed and inefiicient. Certain matter 

 must be imported — it cannot be manufactured. If the raw 

 material is imported but does not reach the cell, then the transport 

 system is at fault. (2) A similar statement could be made about 

 the supply of energy. (3) The cell itself may be at fault — e.g. after 

 HCN poisoning, in spite of adequate supplies of energy and material, 

 metabolism is at a low ebb. (4) The transport trouble might be 

 due to the scarcity of barges, e.g. anaemia, or to want of force in 

 the driving mechanism, e.g. heart failure. (5) In certain patho- 

 logical conditions a cell-community may take the bit between its 

 teeth and overproduce. The immediate result is to hamper its 

 own activities by the presence of the products of its activity. 



To take a specific instance — ^suppose we find that an organ 

 seems to suffer from a lack of oxygen. This may be due (i.) to 



