28 ENDOCRINE THERAPEUTICS 



the great rise of pressure which their contraction 

 produces the larger arteries tend to become 

 passively dilated ; this dilatation may be very 

 great." This must be borne in mind in aneurism 

 and in aortic atheroma. Bainbridge says : " In 

 all probability, the varying activity of the supra- 

 renal glands, brought about by impulses reaching 

 them from the splanchnic nerves, plays an im- 

 portant part in the adjustment of the vascular 

 system to the changes constantly taking place in 

 the body. A striking instance of this adjustment 

 is seen in states of violent emotion, such as rage, 

 pain, or fear. The additional adrenalin sent into 

 the blood stream, in these circumstances, increases 

 the amount of glucose passing from the liver into 

 the blood, thereby providing a further supply of 

 sugar to the skeletal muscles ; and in so far as it 

 raises the blood- pressure, it also improves the 

 nutrition and efficiency of the heart and the blood- 

 supply to the brain. In this way the reaction of 

 the animal to those emotional states, by move- 

 ments of attack or of defence, is rendered more 

 effective." 



To the local effect of adrenalin in causing the 

 contraction of vessels on a bleeding surface, I 

 need not further refer. These seem to me to be 

 the principal points in the physiology of this organ 



