Chapter 12 

 SHOCK AND RELATED PHENOMENA 



THE GENERAL METABOLIC REACTION TO INJURY 



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p to this point, injury has been considered in terms of events 

 within the cell or in the immediate vicinity of areas of damage. 

 The problem of injury, particularly trauma, can however also be 

 considered in terms of the general metabolic reaction of the body. 

 This general reaction is intimately related to the question of 

 "stress." The concept of a "stress reaction" is not new but has been 

 developed particularly by Selye into a general hypothesis whose 

 basis is the stimulation of the secretion of the adrenal cortex by in- 

 jury of many types. The essential feature of the stress hypothesis is 

 that many of the phenomena of the general reaction to injury are 

 due to the effects of the adrenal cortical hormones thus released 

 into the circulation. 



The general reaction to injury may be divided into the im- 

 mediate phase, the phase of shock and the phase of recovery. The 

 most striking feature of the immediate phase is an alteration of 

 carbohydrate metabolism in the direction of increased utilisation. 

 Thus in this stage of injury (the first twelve hours or so) there is 

 an elevated level of blood glucose, a decline in the level of glycogen 

 in skeletal muscle and a rise in the level of pyruvate and lactate in 

 the blood without alteration in their ratio one to the other. There 

 is also a transient increase in the glycogen content of liver. If the 

 body, particularly the liver, is depleted of glycogen prior to injury 

 the rise in blood glucose concentration is considerably lessened. 



The key to these reactions is adrenaline. After injury they do not 

 occur in the absence of the adrenal medulla, the chief source of 

 bodily adrenaline. In addition, the changes listed above can be 

 reproduced in a normal animal by injection of adrenaline (Cori, 

 1931) . The secretion of adrenaline in response to stress is of course 

 a cardinal feature of the reactions to danger and other stressful 

 situations as described some time ago by Cannon (1923) and others. 



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