Surgery of the Autonomic Nervous System
WALTER CANNON,1 in 1929, coined the term “homeostasis” to describe the autonomic mechanism by which the fluid matrix of the mammalian body is maintained in a constant state despite changes in external environment. This is accomplished by the balanced opposition of the sympathetic and parasympathetic divisions of the autonomic nervous system. The sympathetic division provides an emergency protective mechanism which is always ready to go into action to combat any variety of adverse circumstances. When called into action, the sympathetic division uses up the bodily reserves in order to give rise to an increased liberation of body energy and the effects, therefore, are catabolic in character. Some of the more common conditions which arouse it to activity are pain, hemorrhage, infection, asphyxia, extremes in temperature, and any form of intense emotion. The catabolic functions of the sympathetic system are balanced by the anabolic functions of the cranio-sacral or parasympathetic division which come into ascendancy during periods of rest and recuperation, and are of a conservative character. When one of these systems is excited, the other is inhibited.
However, this normally efficient homeostatic balance may break down occasionally, resulting in pathologic states. When this occurs the surgeon may be called upon to alleviate the situation by interrupting the flow of impulses responsible for the abnormal state. A list of such pathologic conditions follows:
Peptic. . .