320 



STOMACH AND INTESTINE. 



its muscular coats * ; in others, the oesophagus 

 has been found greatly thickened ; and in 

 others f, this thickening has also implicated 

 the stomach itself. In other cases J, this organ 

 has been found with a narrowed or hardened 

 pyloric sac, or a dilated and relaxed cardiac 

 extremity or aperture; or even in a state of 

 suppuration. From a comparison of these 

 appearances, it would therefore seem, that the 

 act is often at least assisted by vigorous gas- 

 tric movements. And the existence of such 

 movements is also implied by the fact, that 

 this rumination occurs at the period of diges- 

 tion, when the organ is distended, and its 

 pyloric aperture shut. 



As regards the main feature of the process 

 namely, its subjection to the will, it is im- 

 portant to notice that great variations obtain. 

 Thus, in some of these cases, the expulsion 

 of the food has required a violent effort. In 

 the majority, it has been easily evoked or 

 suppressed. While in others, it has been al- 

 most uncontrollable ; or its non-occurrence 

 at the habitual time has been followed by a 

 painful feeling of fulness, or by the act of vo- 

 miting. 



On the whole, the variable condition of the 

 stomach itself, the slow acquisition of the 

 habit in some subjects, its close resemblance 

 to the easy vomiting of young children, as well 

 as its analogy to voluntary eructation all 

 these circumstances favour the belief, that the 

 unusual effort of volition which forms the 

 main feature of .the act has for its object to 

 open or relax the cardiac orifice and the lower 

 part of the oesophagus. Without such a re- 

 laxation, any further efforts on the part of 

 the active pyloric sac would be inefficient : 

 while, with it, their place might be more than 

 supplied by the presence of powerful abdo- 

 minal contractions. Finally, it is much more 

 consistent with all we know of these two seg- 

 ments of the alimentary canal to suppose the 

 oesophagus capable of being slightly affected 

 by a voluntary effort, than to imagine any 

 part of the stomach placed in the anoma- 

 lous position of a powerful voluntary muscle, 

 its muscular coat sometimes remaining un- 

 affected, sometimes being positively disor- 

 ganized by structural disease. And the hy- 

 pertrophy of the gastric coats, in some of 

 the instances before alluded to, may be in- 

 terpreted as the effect of rumination, quite as 

 much as its cause ; in other words, as being 

 possibly produced by that prolonged gastric 

 movement which would result from such an 

 act, in those instances in which the organ was 

 otherwise healthy. 



Mucous membrane. The mucous mem- 

 brane, on which the functions of the various 

 parts of the intestinal canal essentially depend, 

 is so modified in the stomach, as to offer a 

 complex arrangement, such as remarkably 



* Voigtel. Path. Anat. vol. ii. p. 517. 



f Arnold's Untersuchungen. Zurich, 1838, p. 211. ; 

 Valentin's Lehrbuch, vol. i. p. 273. 



1 Arnold. Lehrbuch der Pathologischen Physio- 

 logic, 571. 



contrasts it with the simpler layer that lines 

 the upper part of the tube.* And it is dis- 

 tinguished from the compound membrane of 

 the intestine by the possession of certain spe- 

 cial structures : namely, the proper gastric 

 cells, or glandular epithelia, as they are some- 

 ' times called. 



The remaining histological constituents of 

 this mucous membrane are similar to those met 

 with in other parts of the canal. A delicate 

 membrane is variously involuted or moulded 

 upon a quantity of areolar tissue. The latter 

 texture, which is thus immediately subjacent 

 to this " basement " membrane, forms the 

 matrix of the mucous coat, and, as such, 

 contains its vessels, nerves, and lymphatics, 

 and connects it with the middle or muscular 

 coat. While on its opposite side, the deli- 

 cate limitary membrane sustains a number of 

 minute cells, that bound the cavity of the 

 tube. 



Examined by the naked eye in situ, the 

 mucous membrane of the stomach is seen to 

 be a tolerably firm but soft layer, of a pale 

 pink colour, which everywhere loosely lines 

 the interior of the muscular coat, and pro- 

 jects from its surface in numerous wrinkled 

 folds. These rugce chiefly occupy the cardiac 

 half of the organ, forming convolutions which, 

 though somewhat irregular, are mainly lon- 

 gitudinal. They are effaced by distention of 

 the stomach. And on putting the mucous 

 membrane on the stretch, we may^ often 

 discern that its whole internal surface is 

 occupied by extremely minute pits or de- 

 pressions-}-; the confluent and projecting 

 intervals of which become so much longer 

 as they near the pylorus, that they may 

 almost be compared to very short and scat- 

 tered villi. These depressions are the open- 

 ings of the stomach-tubes or proper gastric 

 glands. 



The stomach-tubes (c, a, d,fig. 246.) may be 

 described as cylinders of basement membrane : 

 which are packed vertically side by side in a 

 sparing matrix of dense areolar tissue, and are 

 filled by a peculiar cell-growth. Below, they 

 terminate in closed and rounded extremi- 

 ties (rf). Above, they expand slightly before 

 reaching the free surface of the membrane, 

 where their margins finally become continuous 

 with each other, so as to form a series of 

 low ridges, the height and width of which vary 

 somewhat in different parts of the stomach. 

 The length of these tubes is, on an average, 

 about ^ T tli of an inch. But this estimate, 

 which is tolerably accurate as regards the 

 middle of the organ, may be almost doubled 

 for the pyloric, and halved for the cardiac 

 region, a difference which forms the main 

 cause of the very different thickness of 

 the mucous membrane in these two parts. 



* See articles MOUTH, OESOPHAGUS, and PHA- 



KYNX. 



f Such details may be best verified by everting 

 and inflating a perfectly fresh stomach ; and removing 

 the adherent mucus by pouring on it a very gentle 

 stream of water, from a gradually increasing eleva- 

 tion. 



