777 K STOMACH 385 



The general disposition of the peritoneum varies but little in the different species, the 

 only notable diversities being remarked in the great omentum. In the Ox, Sheep, and 

 this is detached from the middle of tlie lower face of the rumen, and envelops the 

 ri'.'ht sac of that organ, fixing (he fourth comp.irtment to its great curvature, and then 

 passing upwards to become continuous with the mesentery. In the Doy and Pig, this 

 t'M descends in front of the intestinal mass until near the pelvis : then it asct nds in 

 gathering on itself, and ultimately spreads over the colon : in t. < middle portion of the 

 great omentum there are, consequently, four layers placed against each other. 



COMPARISON OF THE ABDOMINAL CAVITY OF MAN WITH THAT OF ANIMALS. 



The abdominal cavity of Man is elongated vertically, and has an inferior cavity 

 occupying the entrance to the pelvis. There is nothing particular to note in its disposi- 

 tion, the differences observed in it being allied to the external shape of the body. Tho 

 peritoneum is spread over its purietes nearly in the same manner as in the Carnivore ; 

 the great omentum is constituted by four layers, and covers the intestines like an apron : 

 between its two laminae is the letter cavity of the omcutum, virtually in the adult. 



THE STOMACH. 



The stomach is a membranous sac comprised between the oesophagus 

 and intestines, and in which are commenced the essential phenomena of 

 digestion. 



1. The Stomach in Sollpeds. (Figs. 182, 183, 184, 185, 186.) 



Preparation. In order to study the relations of this organ, it suffices to open the 

 abdomen and remove tlie intestinal mass in the following manner : Place the animal in 

 the first position, and very slightly inclined to the left side ; make an incision through 

 the inferior abdominal wall, or, still better, carry it away entirely by a circular incision, 

 taking care not to wound any part of the intestine. The entire viscera should then be 

 withdrawn from the abdominal cavity, and laid on the table which supports the subject ; 

 for this mass omnot be allowed to fall on the ground without risk of being pulled and 

 torn, either in the intestine itself, or those parts which it is desired to preserve intact in 

 the abdomen. Incise the floating colon where it joins the rectum, and the duodenum 

 where it passes behind the great mtscnteric artery ; the base of the caecum should now 

 be detached from the sublumbar surface by the rupture of the cellular tissae which 

 connects it to the right kidney and the pancreas ; the cellular connection between the 

 latter gland and the terminal extremity of the fourtli portion of the large colon should 

 also be broken ; after this, it is only necessary to divide the attachment < f the mestnterie 

 bands to the sublumbar region, with the vessels contained between them. The intestinal 

 mass is then definitively expelled from the abdominal c.ivity . In this way it is possible to 

 expose, and conveniently prepare, not only the . -t"inacli, )>ut also the spleen, liver, pancrea--, 

 kidneys, ureters, > (>. nothing more remains than to make known the procedure to bu 

 adopted in everting the stomach, in order t" study its internal surface, or dissect its deep 

 Mar layer. It is recommended, first, to excise the stomach with at least three inches 

 i tii.- oesophagus, and eight inches of the duodenum, and cleanse the interior of the organ. 

 This may be done in several ways, but the following is the simplest : a certain quantity 

 of water is introduced into the stomach by fixing the duodenum f > a \\ater-tap, the 

 rL'lit hand manipulating the organ while the left closes tlie duodenum to prevent the 

 escape of the liquid. The alimentary substances contained in it ate m u'u's way mhrod 

 with the water, and may be expelled' from the duodenum by pressing the stomach ; this 



ion being repeated four or five times, thoroughly cleanses the cavity of the organ. 



rt the inner surface, it is only necessary to introduce by the duodenum a loop rf 

 md make it paw through the oesophagus; a strong waxed thread is fastened in 



the l<:op and firmly fixed around the (esophagus, when, in pulling back the wire, thi- 

 rty i- duiwn towards the pylorus, and by careful traction the latter is BO dilated 

 as to allow the pat-sage of the cardiac end, and complete cvcraion of the stomach. Inflation 

 will then give a its normal form and disposition ; with this dinVremv. tLut the mucous 

 incjiil.rane is external, and the serous tunic internal. 



Lastly, to render the muscular layers of the stomach more evident, it is advisable to 

 plunge the organ into boiling water for some minutes, after which it should be put into 

 \ uter. It it is desired to study the external and middle layers, the stomach should 

 be inflated, and its serous covering removed by stripe with forceps and the fingers; if tlie 

 deep layer is to be examined, the mucous membrane must be removed by means of the 

 fojwps and ncnlppl from a stomach previously evert- d. 



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