Release of Function in the Nervous System. 203 



to creep into some sheltered place, and to lie curled up until he either 

 dies or recovers. All capacity to move the body as a whole is abolished ; 

 the reactions of the part affected now dominate the activity of the complete 

 animal. Visceral reflexes of this order are antagonistic to general move- 

 ments, and this is expressed not only in muscular immobihty but in the 

 mental attitude which accompanies visceral pain ([7], p. 373). 



Eeferred pain of visceral origin and the tenderness which accompanies it 

 may be confined to the territory of a few segments only, representing the 

 nerve supply of the affected organ. But if the stimulus is extremely 

 severe, as, for example, during an attack of gall-stone or renal colic, the 

 pain may spread widely even in otherwise normal persons. Not only does 

 it become bilateral, but it is liable to extend both upwards and downwards 

 into regions that stand in no direct nervous relation with the affected organ 

 ([4], p. 104). 



Should a referred pain become chronic, this forms an even more important 

 cause for its diffusion. It tends to spread by the fact of its duration. For 

 not only is the general resistance of the patient worn down by the disease, 

 but the passage of painful impulses is facilitated by time. 



Certain segmental areas seem to be related to one another, although they 

 are situated far apart on the body. Organs such as the uterus and the 

 breast stand in a close mutual connexion, and within twelve hours of labour, 

 referred pains not uncommonly appear in the' front of the chest and in the 

 scapular regions ; these come and go with the " after pains," and can be 

 increased by the action of ergot or by manipulating the uterus. 



These phenomena of " generalisation " or " spread " of visceral pain and 

 tenderness are of such common occurrence that they form an important 

 factor in the clinical picture of many diseases ( [4], p. 105). Diffusion of 

 painful sensations is due to diminished central resistance ; potentially 

 painful impulses are allowed to spread widely, which would normally 

 have been inhibited or strictly confined to areas appropriate to the organ 

 affected. 



The general bodily state associated with menstruation forms one of the 

 most potent causes of diminished automatic control. This physiological act 

 may be accompanied by referred pain, confined strictly to those segments 

 which stand in direct relation with the pelvic organs ; or the morbid 

 sensations may occupy the whole of the body and lower extremities below 

 the level of the umbilicus, with or without the cervical areas and occipital 

 region of the scalp. Finally, the head, trunk, and even the limbs may 

 become painful and tender in parts that have no direct relation to stimuli 

 within the pelvic organs. The extent to which such widespread generalisation 



