CHAPTEE VI 



SYMPATHETIC SYSTEM 



CONTENTS. 1. Anatomy and histology of fibres and ganglia of sympathetic 

 system. 2. Peripheral distribution of sympathetic system to the organs which it 

 innervates. 3. Physiological arrangement of constituent parts of sympathetic 

 system ; origin and course of efferent fibres. 4. Origin and course of afferent 

 fibres. 5. Function of peripheral ganglia. Bibliography. 



THE Sympathetic System, while intimately connected with the 

 cerebrospinal axis, differs from it in many respects, especially in 

 its peripheral distribution. This is evident from the important 

 researches of Langley, to whom we are chiefly indebted for our 

 knowledge of this subject. 



Just as the lumbo-sacral part of the cord is able to function 

 after it has been separated from the cervico-thoracic segments, so 

 the sympathetic system is able to recover and maintain certain of 

 its functions at least for a time and under given conditions of 

 existence and nutrition after extirpation of those segments of the 

 spinal cord with which it is anatomically connected (Goltz). 



On account of this property, by which the system which 

 controls the visceral and involuntary functions of the body is 

 distinguished from the spinal nerves that innervate the somatic 

 organs and depend wholly on their connections with the central 

 nervous system, Langley has proposed to replace the term 

 Sympathetic System by the more physiological title Autonomic 

 Nervous System. But since this autonomy is incomplete, and 

 there are close anatomical and physiological relations between the 

 visceral system and the cerebrospinal axis, it seems more con- 

 sistent to retain the older nomenclature. 



In discussing the functions of the visceral organs in the first 

 two volumes we laid stress on the physiological importance of 

 individual parts of the sympathetic system ; in the present 

 chapter we have to deal with this system as a whole and with its 

 general characteristics. 



I. The sympathetic nervous system consists of a highly com- 

 plex arrangement of ganglia, nerve-fibres, and nerve-plexuses, 

 which are distributed to the different regions of the body. 



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