76 THE ACTION OF THE LIVING CELL 



servations made upon dogs which had been brought 

 into a state of shock by various experimental means, 

 such as exposure of the abdominal viscera to a draught 

 of air, and the injection of stomach contents. In these 

 experiments it was noted that coincident with the on- 

 set of shock, the stomach and intestines assumed a dark 

 blue color due to stagnation of blood in the vessels. 

 In experiments in which both arterial and venous pres- 

 sures were recorded, it was noted that during shock 

 the veins and viscera showed an increased pressure, 

 whereas the arterial pressure dropped below the nor- 

 mal value. As the depth of shock increased, stagnation 

 in the visceral vessels was found to increase, the intes- 

 tinal vessels becoming engorged more rapidly than 

 those of the stomach. When means were taken to re- 

 vive the animals, the reverse of the above changes took 

 place, the congestion being reduced and the arterial 

 circulation reestablished. On the basis of such obser- 

 vations the conclusion was drawn "That we cannot 

 apparently experimentally produce profound shock 

 without the occurrence of congestion and that the re- 

 duction of such shock does not occur until we reduce 

 the congestion and distribute the blood over the sur- 

 face." In all subsequent experiments in which shock 

 was produced, this stasis of blood in the visceral ves- 

 sels was always found. It is this visceral congestion 

 which is responsible for the various external symp- 

 toms of shock, such as weakened pulse, diminished 

 respiration, and lowered temperature. 



The splanchnic circulation, physiologically con- 

 sidered, is distinct from the somatic or peripheral cir- 

 culation, there being an inverse relation between the 

 volume of blood circulating in the vessels of the 



