144 MAN --AN ADAPTIVE MECHANISM 



Relation of the Adrenals to Distance Ceptor Stimulation 



The effect of driving the adrenals is to produce an 

 increased secretion of adrenin, the effect of which 

 in turn is the production of many of the gross phenom- 

 ena of fear and other emotions, which are also the 

 phenomena of great physical exertion. The effect 

 of adrenin upon the mechanism by which heat and 

 motion are produced in the body is immediate and 

 specific. Adrenin causes an increased output of sugar 

 from the liver ---the chief fabricator of the body 

 fuel and increases the facility with which sugar is 

 consumed in the muscles. When injected into the 

 blood stream, adrenin augments the vigor of the 

 circulation, increases the blood-pressure and the force 

 and frequency of the heart beat and diverts much 

 of the blood supply from the internal organs of 

 digestion and procreation to the skeletal muscles, 

 the lungs and, perhaps, the central nervous system 

 (Cannon). 



Simultaneously with the stimulation of organs and 

 tissues necessary to motor activity and the inhibition 

 of organs non-essential to motor activity, adrenin 

 causes erection of the hair, dilation of the pupils, wid- 

 ening of the nostrils, increased activity of the sweat 

 glands, acceleration in the rate and alteration in the 

 rhythm of respiration, rise in body temperature, pallor, 

 trembling, dry mouth, muscular relaxation many 

 of the phenomena, in short, of fear and rage ; phe- 

 nomena which are also a part of the preparation for 

 an act of supreme muscular exertion. According to 

 Elliot, adrenin performs every function of which the 



