1630 



HUMAN ANATOMY. 



denum (the fixation being due to the relation of the superior mesenteric artery and 

 to the root of the mesocolon in front), while above the cardiac end is suspended 

 from the oesophagus and held in place by the gastro-phrenic and gastro-splenic liga- 

 ments. The transverse colon may then lie in front of the stomach and may, if dis- 

 tended, be taken for it. The empty stomach lies upon the posterior abdominal 

 wall, 'if the emptiness is habitual, the pylorus will resemble the first portion of 

 the duodenum and regurgitation of duodenal contents is exceptionally easy. The 

 "gnawing pains" of hunger or starvation (distinct from the sensation of hunger 

 itsdi) are at least partly due to the traction on the nerve-plexuses and filaments 

 resulting from this altered position, and can, therefore, in many cases be relieved 

 temporarily and partially by tightening the clothing about the waist and abdomen, 

 giving support to the viscera. 



When the stomach is distended the enlargement, which occurs at first upward 

 and backward and towards the left side, raises the arch of the diaphragm in that 

 region and with it the heart and pericardium. The gastric plexuses derived from 

 the two pneumogastrics and the associated sympathetic fibres, together with the 

 coronary plexus from the sympathetic, are all in close relation with the lesser 

 curvature, especially its cardiac end. It is not, therefore, difficult to understand 

 how this change in the position of the stomach aids in producing the flushed 

 face, embarrassed respiration, and irregular heart action often seen in various forms 

 of dyspepsia or after overeating. If distention continues, the right lobe of the 

 liver is also pushed upward, the pylorus moves to the right, and the transverse 

 colon downward ; the stomach comes in close contact with the anterior wall of the 

 abdomen, the " scrobiculus cordis" (page 171) is obliterated, and a tympanitic 

 note replaces the normal resonance. 



Conversely, cardiac disease may cause vascular congestion of the stomach, 

 catarrh, dyspepsia, or even heematemesis. The " black vomit" of moribund per- 

 sons is due to a similarly produced distention and rupture of the stomach capillaries. 

 The position of the stomach varies with the respiratory movements. In forced 

 inspiration the cardiac opening descends about one inch with the crura of the dia- 

 phragm ; the pylorus reaches about the level of the umbilicus. 



Eructation of stomach contents in its typical form is accomplished by con- 

 traction of the muscular walls of the stomach ; vomiting by compression of the 

 stomach against the under surfaces of the liver and diaphragm through contrac- 

 tion of the abdominal muscles. This is associated with contraction of the circular 

 pyloric fibres and relaxation of the oblique fibres at the cardia, and is probably 

 aided by contraction of the stomach walls themselves. 



It is obvious that a full stomach is more easily and directly compressed in this 

 way, and therefore the ingestion of large quantities of fluids favors emesis. 



Vomiting is a clinical symptom often of the greatest significance, and should 

 be studied in relation to the pneumogastric and sympathetic distribution to the 

 stomach, lungs, and abdominal viscera ; and its various causes central, reflex, and 

 direct should be worked out systematically. 



hi ji<rifs <>/' th<- Stomach. The changes in position and the degree of distention 

 are of the utmost importance in trauma expended upon the stomach, which, if quite 

 empty, almost certainly escapes contusion and rupture. It is, at'any rate, much less 

 frequently ruptured than the intestines on account of its thicker walls and of the 

 protection afforded it by the overhanging ribs and the interposed liver. The 

 "stomach-bed " (page 1620) supplies an elastic and movable base of support, which 

 also favors it> escape from injury. 



In penetrating or gunshot wounds its condition as to emptiness or the reverse 

 is even more important. \Vhen either wall is opened by rupture or wound, eversion 

 of the mucous membrane, which is favored l>y its thickness and by the laxity of the 

 sulmiucous connective tissue, may temporarily plug the opening, and through the 

 formation of adhesions permit of spontaneous cure. The different directions of 

 the muscular fibres in the three layers of that coat ordinarily prevent wide separa- 

 tion of the margins of the wound, and thus also favor its closure by natural processes. 

 In escape of stomach contents through ulci-ration, wound, or rupture, if the poste- 

 rior wall is involved, the K^ser omental cavity is infected, and a localized sub- 



