656 ' TEXT-BOOK OF PHYSIOLOGY 



NOTE. Langley to whom we are so largely indebted for the present state of our 

 knowledge of the anatomy and physiologic relations, not only of different portions 

 of this system, but of the system in its entirety, introduced the term " autonomic," 

 on account of the insufficiency of the older nomenclature, e.g., "sympathetic," 

 "ganglionic," "vegetative," "organic," "visceral," etc., to fully express its ana- 

 tomic relations and physiologic action. By this term it is implied that this system is 

 independent in action; that is, independent of volitional control, that its activity 

 is determined by nerve impulses coming from the periphery, though subject to 

 modifications by cerebral states of an affective or emotional character. Thus he 

 states (Journal of Physiology, vol. 23) " I propose to substitute the word auto- 

 nomic " * * *; "the autonomic nervous system means the nervous system of the 

 glands and of the involuntary muscle." "I propose the term autonomic nervous 

 system for the sympathetic system and the allied nervous systems of the cranial 

 and sarcal nerves and for the local nervous system of the gut " * * *. "I conclude 

 that there is no fundamental difference between the pre -ganglionic fibers of the 

 body, whether they belong to the cranial, the sympathetic or the sacral autonomic 

 systems." "The word autonomic nervous system consists of the sympathetic sys- 

 tem, of the cranial autonomic system, and the enteric system, the plexuses of 

 Auerbach and Meissner." 



Gottlieb and Meyer, partly on the basis of the difference in the physiologic 

 action of certain drugs on different portions of this system, and partly on the ap- 

 parent antagonism in the action of the nerves which arise from the bulbar and 

 sacral region of the spinal cord, to those which arise from the thoracic and upper 

 lumbar regions, proposed a modification of the terminology. Thus they applied 

 to the entire system the term "vegetative," but at the same time retained the term 

 autonomic for the fine medullated pre-ganglionic fibers in the cranio-bulbar and in 

 the sacral nerves, i.e., those nerves not in physiologic relation with the chain of 

 sympathetic ganglia, though related to peripheral ganglia. The pre-ganglionic 

 cranio-bulbar and sacral nerve-fibers together with their post-ganglionic continua- 

 tions innervate the anterior and posterior ends of the digestive tract and associated 

 structures respectively, while the pre-ganglionic thoracico-lumbar nerve-fibers and 

 their ganglionic continuations innervate the sweat-glands and blood-vessels of the 

 head, face, extremities and the body-walls and the blood-vessels and muscle- walls 

 of the abdominal viscera. Associated with these latter nerves are the efferent fibers 

 of the vagus which innervate the heart, the blood-vessels and glands of the viscera 

 of the thorax and part of the abdomen as well. 



By reason of the double innervation of various organs of the body and the op- 

 posite effects produced by stimulation on the one hand of the autonomic cranio- 

 bulbar and sacral nerve-fibers and on the other hand of the pre- and post-ganglionic 

 fibers of the thoracico-lumbar nerves, Gottlieb and Meyer concluded, that there is 

 a fundamental difference in the functions of the cranio-bulbar and sacral regions 

 and the thoracico-lumbar regions of the spinal cord. This antagonism is shown 

 by the effects observed in the iris and in the action of the heart by alternate stimula- 

 tion of the cranio-bulbar and thoracic fibers which are distributed to these struc- 

 tures. It should be borne in mind, however, that even though pre-ganglionic 

 fibers leave the spinal cord by way of the thoracic nerves, the nerve-cells from which 

 they arise may lie in other and even distant regions. Thus it is well known that 

 the vaso-motor center which through thoracic nerves constricts the blood-vessels 

 of the salivary glands, the mucous glands of the mouth and nose lies high up the 

 bulbar region, not far from the vaso-dilatator center, which through bulbar fibers 

 (in the chorda tympani and glosso-pharyngeal) supplies and dilates the same blood- 

 vessels of the corresponding structures. It is also believed that the dilatator pupillae 

 or iridis center which, through nerve-fibers that leave the spinal cord through the 

 second thoracic nerve and then pass upward in the sympathetic chain to the supe- 

 rior cervical ganglion and thence to the dilatator fibers of the iris, is also located 



