FUNCTIONAL ABNORMALITIES 



Nervous Disturbances — Disturbances of Motion. 



The nervous system regulates the functions of the organs and 

 is the intermediary between the corporeal and psychical func- 

 tions of the polycellular animal organism. The nervous matter 

 may be excited by both external and internal agencies (stimuli), 

 and being thus stimulated gives to the tissues the impulse for 

 the manifestation of the powers peculiar to them. Alterations 

 in the excitability of the nervous system and abnormal stimuli 

 which occasion such variations, may result in functional dis- 

 turbances of the nervous apparatus and the organs dependent 

 upon it. Where the whole central system is altered, these dis- 

 turbances are general and may manifest themselves in the widest 

 possible range (general nervous syinptojns) of abnormal nerv- 

 ous phenomena (sensory, motor, secretory, reflex). Where 

 definite localities in the central nervous system are subjected 

 to injury, we speak of central local involveynent and focal symp- 

 toms. In this connection, too, nuclear involvement where the 

 nucleus is affected, is differentiated from supra-nuclear in- 

 volvement, where the course of the conduction within the 

 central system — that is. above the level of the nucleus — is 

 the part disturbed; and according as the focus affected lies 

 within the brain, in the medulla oblongata or in the spinal cord 

 the lesion is said to be cerebral, bulbar or spinal. Where a 

 nerve is injured in its course beyond its point of exit from the 

 brain or spinal cord to it's area of distribution or wdthin the 

 latter, peripheral aft'ections ensue. 



General Nervous Disturbances. — The brain and medulla to- 

 gether constitute the central organ presiding over the whole 

 category of functional activities, and therefore everything which 

 causes depression or excitation of cerebral activity must of nec- 

 essity bring about a great variety and general distribution of 

 disturbances. Every lesion of the deeper centres of the medulla 



