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HANDBOOK OF PHYSIOLOGY 



NEUROPHYSIOLOGY I 



semblance between the ganglia of the fifth cranial 

 nerves and those of the posterior roots, and Bichat 

 (145), the brilliant French pathologist who died so 

 young, had gone so far as to associate all ganglia with 

 the nervous processes of involuntary, unconscious 

 'organic' life. 



The differentiation between the ganglia found in 

 the sympathetic nersous system and those on the 

 roots of the central nervous system was to come later. 

 Charles Bell made the distinction but admitted he did 

 not know what role was pla\ed b\- the .sympathetic 

 nerves or by their ganglia (146). His many studies on 

 the fifth and seventh cranial nerves (146-148), illus- 

 trated by his own beautiful drawings, are classics, and 

 his demonstrations of the function in the nerves of 

 the face are perpetuated in the name Bell's palsy. 

 Bell had come from Edinburgh to the famous ana- 

 tomical school that William Hunter had founded in 

 Great Windmill Street near Piccadilh'. A brilliant 

 di.ssector but not primarily an experimentalist. Bell 

 relied heavily on his brother-in-law, John Shaw, in 

 this aspect of his work and suffered a great loss when 

 Shaw died. 



In the cord the various columns had been dissected 

 by the anatomists and the grouping together of nerves 

 in such larue bundles had certainly seemed suggestive 

 of parcellation of function. But not all anatomists 

 were agreed. Bichat on dissecting out some nerve 

 filaments found them centrally located in the lower 

 cord but more lateral higher up. He therefore con- 

 cluded that although the filaments had individual 

 properties, the fasciculi were mixed. The idea per- 

 sisted, however, that the columns and also the spinal 

 roots might have different functions according to 

 whether they were anterior or posterior. An early idea 

 was that the anterior roots carried Ijoth motor and 

 sensory supplies for the muscles while the posterior 

 roots gave a sensory service for the skin. An Edinburgh 



145. Bichat, Marie Francois Xavier (1771-1802). Aualomie 

 generale, appliquee a la physiologie el a la medecine. Paris: 

 Brosson, 1801, 2 vol., English translation by G. Hay ward 

 Boston: Richardson and Lord, 1822. 3 vol. 



146. Bell, Charles (1774-1842). The Nervous System of the 

 Human Body as explained in a series of papers read be/ore 

 the Royal Society 0] London. Edinburgh: Black, 1836. 



147. Bell, C. On the nerves; giving an account of some ex- 

 periments on their structure and functions, which lead 

 to a new arrangement of the system. Phil. Trans. 1 1 1 : 398, 

 1 82 1 . 



148. Bell, C. Of the nerves which as.sociatc the muscles of the 

 chest in the actions of breathing, .speaking, and expres- 

 sion. Being a continuation of the paper on the structure 

 and functions of the nerves. Phil. Trans. 112: 284, 1822. 



anatomist, Alexander Walker Ci49)> suspected that 

 they might serve .separate roles but unfortunately 

 picked the posterior root as the motor and the 

 anterior root as sensory. 



In 181 I a small pamphlet was pri\-ately primed, 

 entitled Idea oj o new anatomy of the brain suhmitled jir 

 the observation of his friends. The author was Charles 

 Bell (150). This pamphlet had no general distribution, 

 no more than 100 copies being printed. (Only three 

 are known to exist today, one of which is in the Na- 

 tional Library of Medicine in Washington; in Eng- 

 land, copies can be seen at the British Museum and 

 at the Royal Society.) Bell stated that the purpose of 

 this pamphlet was to assure his friends that in his dis- 

 sections of the brain he was investigating its structure 

 and not searching for the seat of the soul. In this work 

 he stated his opinion that nerves owe their differences 

 in properties to their being connected to different 

 parts of the brain. He said that, holding this opinion, 

 he wondered whether the double roots of the spinal 

 nerves might indicate that "nerves of different en- 

 dowments were in the same cord, and held together 

 by the same sheath." To test this idea experimentally, 

 he cut "across the posterior fasciculus" and noted 

 that there were no convulsive movements of the 

 muscles of the back; but that on touching the anterior 

 fa.sciculus with the point of a knife, the muscles of the 

 back were immediately convulsed. From this experi- 

 ment he concluded at that time, "The spinal nerves 

 being double, and having their roots in the spinal 

 marrow, of which a portion comes from the cerebrum 

 and a portion from the cerebellum, they convey the 

 attributes of both grand divisions of the brain to every 

 part, and therefore the distribution of such nerves is 

 simple, one nerve supplying its distinct part." 



It may be noted that there is in this pamphlet no 

 suggestion that the posterior columns or roots might 

 be sensory in function. Bell considered the cerebellum 

 to be concerned with involuntary and unconscious 

 functions ("the .secret operation of the bodily frame" 

 and "the operation of the viscera") whereas he recog- 

 nized the cerebrum "as the grand organ by which 

 the mind is united with the body. Into it all the nerves 

 from the external organs of the senses enter; and from 

 it all the nerves which are agents of the will pass out." 



149. Walker, Alexander (1779-1852). New anatomy and 

 physiology of the brain in particular, and of the nervous 

 system in general, -irch. Universal Sc. 3: 172, 1809 



1 fjo. Bell, C. Idea of a new anatomy of the brain submitted for the 

 observation of his friends. Privately printed, 1811; repro- 

 duced in J. F. Fulton. Selected Readings in the History of 

 Physiology. Springfield: Thomas, 1930, p. 251. 



