Physiological therapeutics : a new theory / by Thomas W. Poole.

  • Poole, Thomas W.
Date:
1879
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Licence: Public Domain Mark

Credit: Physiological therapeutics : a new theory / by Thomas W. Poole. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    THE OESOPHAGUS AND STOMACH. I45 consequently in abeyance, the muscular walls pass into a state of contraction, and so constrict the calibre of the tube as to arrest the further passage of the superimposed injesta. Could any stronger proof be demanded in justification of the truth of our theory ? Dr. Carpenter, however, further remarks, that the action of the cardiac sphincter is reflex, and is dependent on the ' nervous circle ' furnished by the pneumogastric nerves and their ganglionic centres, would appear from the fact that when the trunks of these nerves are divided, the sphincter no longer contracts, and the food regurgitates into the oesophagus.* This statement is hardly quite in accord with the previous quotation. And yet, both may be strictly true, for, as this distinguished physiologist adds, ^' The re-opening of the cardiac orifice, on pressure from within, is one of the first of that series of reversed actions which constitutes the act of vomiting.f May we not see the explanation of the opening of the cardiac sphincter and the regurgitation of the food from the stomach, in the contraction of the muscular coats of the latter, liberated from the restraint of nerve-force by section of the vagi; thus occasioning the '* pressure from within, which could not occur if the organ were paralyzed : just as the contraction of the lower third of the oesopha- gus, under similar conditions, caused the sudden ejection of the food upwards into the mouth, as stated by Dr. Dalton } 264. In the very animal referred to in these experiments, Dr. M. Hall found that '* the simple contractility of the muscular fibre [of the oesophagus] occasions a distinct peristaltic movement along the tube, after its nerves Jmve been divided, causing it to discharge its contents when cut across. J 265. We have further to quote as follows:—^'The office of the gastric branches of the vagi nerves, appears, from Dr. Reid's experi- ments, to be, chiefly, to control the movements of the muscular coat of the stomach. Mechanical irritation of these nerves causes slow and vermicular contractions of this tunic. Section of them may cause in tlie first instance vomiting and loathing of food.|| The reader will please note the significance of the words we have placed in italics, and also the further fact that irritation by no means necessarily implies stimulation, and is much more likely to be equi- valent to paralysis ; for the molecular arrangements which determine the relation of nerve-force to muscular fibre, when deranged, are temporarily overthrown, as in the action of electricity, and while so deranged—that is while the irritation lasts—may be held to set muscular fibre free, 266. The effect of electricity, here, as elsewhere, is to cause uni- versal contractions of muscular fibre, as is seen in the glottis oeso- phagus and'intestines. If what we have already urged, on the paralyzing effects of this agent on nervous tissue, be true, this fact, * Physiology, p. 404. t Ibid. J Ibid. liDrb. Todd 6^ Bowman's Physiol. Anat., p. 493.