318 



STOMACH AND INTESTINE. 



by, a contraction of the muscular coat of the 

 stomach itself. But there is no sufficient 

 reason for supposing that an anti-peristalsis 

 ever obtains, far less for imagining that it 

 constitutes a special element of this expulsive 

 process. 



We may, perhaps, find some corroboration 

 of this statement in the circumstances which 

 constitute, so to speak, the juvantia and 

 lesdentia of this complex act. Perhaps the 

 easiest variety of vomiting is that which fre- 

 quently occurs in the sucking child. Here 

 it is probable that three conditions, each of 

 which might have some influence in facilitating 

 the return of food, are all present at once : 

 namely, a distended stomach, an active gas- 

 tric movement, and the peculiar form of de- 

 glutition which continuous sucking would 

 imply.* The first of these three circumstances 

 would mainly act by affording a greater re- 

 sistance to the abdominal pressure; which 

 although probably reduced to a minimum, is 

 no doubt necessary to the process. And the 

 second may perhaps constitute one of the chief 

 occasions of this regurgitation, by impelling 

 the contents of the stomach through the 

 cardiac orifice. While the latter aperture 

 might be thrown open by some slight and 

 accidental -f irregularity in the act of degluti- 

 tion. 



These conjectures are strengthened by the 

 observation, that distention of the stomach, 

 from any cause whatever, appears greatly to 

 facilitate the occurrence of vomiting. That 

 experience of this act, which a sea-voyage 

 affords, may suffice to recall to most readers 

 how much more easily the process goes on 

 in a moderately full stomach than in an empty 

 one. It is for the same reason that copious 

 draughts of water are used to assist the action 

 of emetics. And during the vomiting of both 

 Man J and animals , the stomach is often 

 gradually distended with air by a series of 

 involuntary " retchings," which thus probably 

 afford a similar assistance to the process. || 

 In like manner, it is to that distention of the 

 whole belly which intestinal obstruction pro- 

 duces, that we must ascribe the peculiarly 

 easy character of the vomiting that is then 

 set up. The easy vomiting which occurs in 

 cases of pyrosis may be similarly explained. 



In addition to these mechanical elements of 

 the process of vomiting, there are others which, 

 though less constant, must not be overlooked. 



* Schultz and Salbach (Valentin's Lehrbuch, 

 vol. i. p. 281.) seek to explain the vomiting of 

 infants by the peculiar form of the stomach at this 

 age. But comparative anatomy entitles us to doubt 

 whether the mere absence of a cardiac pouch would 

 imply such a result. And I believe that their de- 

 scription somewhat exaggerates this peculiarity. 

 For the stomach of the mature foetus often has a 

 cardiac extremity not much less projecting than 

 that of the adult. 



t Compare Beaumont, p. 62. 



j Le'pine, foe. cit. 



Magendie, foe. cit. 



|| This so-called deglutition of air has a close re- 

 semblance to that which precedes voluntary eructa- 

 tion. Its chief conditions seem to be, a spasmodic 

 action of the oesophagus, and a patulous cardia. 



For not only do they take a frequent share 

 in the phenomena of this act, but they also 

 remarkably indicate its co-ordinate nature 

 and arrangement. Thus the act is generally 

 ushered in by a feeling of indistinct uneasiness, 

 distention, or even pain, in the gastric region ; 

 which is often attended by an increased secre- 

 tion of saliva, and a loathing of food, that is 

 soon heightened into positive nausea. This 

 is shortly followed by giddiness, dimness of 

 sight, and languor: symptoms which are 

 evidentl}' of cerebral origin. Next occur the 

 retchings, or efforts at vomiting, before alluded 

 to; which arc probably irregular movements of 

 the oesophagus, unaccompanied by abdominal 

 pressure. Where the stomach is but little 

 distended with fluid, these movements often 

 seem to favour the subsequent occurrence 

 of vomiting, by filling the organ with air. 

 Finally, an uncontrollable effort so far re- 

 verses the ordinary action of the muscles of 

 respiration, as to bring into one period con- 

 tractions which usually occupy different and 

 alternate times. An energetic closure of the 

 glottis follows the descent of the diaphragm ; 

 so that this muscular septum is fixed by 

 the distention of the thorax, as well as by 

 the contraction of its own fibres. And the 

 abdominal muscles now contract violently 

 upon the stomach. During each actual effort 

 of vomiting, the compression which is ex- 

 ercised by the muscles of the trunk causes 

 the head to become greatly congested ; so 

 that the features are red and swollen, and 

 the large veins of the face and temples visibly 

 dilated. The pulse is also quickened ; and 

 the skin often rises in temperature, and per- 

 spires. The expulsion of the contents of the 

 stomach from its cavity is sometimes attended 

 by great pain, which is referred to the lower 

 part of the oesophagus. And in spite of what 

 is apparently a tolerable (though reversed) 

 imitation of the movements of deglutition, a 

 good deal of liquid generally eludes the 

 curtain of the soft palate, and gushes through 

 the respiratory channel formed by the nasal 

 fossas and nostrils. The subsequent pheno- 

 mena mainly depend on the origin of the 

 vomiting. Where, as is often the case, its 

 immediate cause is removed by the expulsive 

 act itself, the patient soon recovers his normal 

 condition. 



A proper consideration of the various 

 causes of vomiting would belong rather to a 

 medical than to a physiological treatise. We 

 need but point out that they may all be 

 divided into two classes: (1) those in which 

 there is an irritation of the nervous centre it- 

 self; and (2) those in which an irritation, 

 applied to the nervous periphery, is trans- 

 mitted thence to the centre, from whence it is 

 reflected into the various organs which con- 

 stitute the agents of the expulsive process. 

 As examples of the first class, we may adduce 

 the frequent instances in which vomiting ac- 

 companies a cerebral injury * or disease. As 



* To such centric irritations might also be referred 

 that kind of vomiting which sometimes results from 



