938 



PERITONEUM. 



It seems as though the gall-duct in gaining 

 the shortest route from the liver to the duode- 

 num had carried out the superjacent peritoneum 

 from the cardiaand lesser gastric curvature into 

 a fold, as far out as the position of the straightest 

 line from the porta to the pylorus; that this 

 fold would have projected in the middle line, 

 but that the enlargement of the right lobe of the 

 liver displaced its posterior part with the cardia 

 to the left, whilst the duodenum being brought 

 into adhesion with the posterior abdominal 

 walls displaced its anterior part to the right, 

 and that both displacements have resulted in 

 an almost transverse instead of an antero-poste- 

 rior horizontal direction. In many vertebrate 

 animals, especially those below the class Mam- 

 malia, the duodenum is not adherent to the 

 posterior abdominal parietes, and the pylorus as 

 well as the cardia is frequently in the middle 

 line, whilst the two lobes of the liver are of 

 pretty equal transverse extent ; in such cases 

 the lesser omentum extends antero-posteriorly 

 in the middle line, f/gs. 490, 491,) and this, 

 we consider, is its typical position. This point 

 will be more fully considered when we come to 

 a particular description of the omenta; at pre- 

 sent we are endeavouring to demonstrate the 

 continuity, merely, of the peritoneum through- 

 out: it is the existence of the omenta, or rather 

 their distorted position in the human subject, 

 that renders this demonstration so difficult. 



It is necessary at this stage of our description 

 to study the peritoneal sheet, or bag, with two 

 free surfaces, called the greater omentum. On 

 making an incision, as above, through the abdo- 

 minal parietes, the liver and stomach are at 

 once brought into view ; but the small intes- 

 tines are concealed by the great omentum co- 

 vering them in front. It is a membraniform 

 apron, having plentiful reticulations of vessels, 

 and often loaded with fat, especially near the 

 vessels. Viewing it undisturbed it appears to 

 be pendent from the greater curvature of the 

 stomach, and to have a free inferior border 

 touching, usually, the pelvic region ; but on 

 lifting it up and looking at its posterior aspect, 

 it is seen to be attached also to the transverse 

 portion of the colon, which at once informs one 

 that it is double. The fact of its being double, 

 however, may be much more strikingly demon- 

 strated in the following manner. If a catheter 

 be held in the foramen of Winslow, and air be 

 blown through it, the great omentum (provided 

 there be no abnormal breach of continuity or 

 adhesion in it) will become inflated like a great 

 bladder ; the inflation extending, not only 

 downwards below the greater curve of the sto- 

 mach, but to the left beyond its fundus, and 

 also to the lesser omentum. The cavity so in- 

 flated is called the sac of the omentum, or the 

 posterior cavity of the peritoneum, and the fo- 

 ramen of Winslow is the orifice that leads to this 

 sac the neck that connects together the ante- 

 rior and posterior cavities of the peritoneum, 

 making them one. 



The foramen of Winslow is not generally big 

 enough to admit more than one or two fingers 

 to be passed through it ; but an incision being 

 made through the lesser omentum, the hand 



may be introduced into the omental sac and 

 passed downwards behind the stomach and in 

 front of the transverse colon, until it reaches the 

 lowermost extent of the great omentum, or bot- 

 tom of the great omental pouch ; it will thus be 

 between the two layers of what we considered 

 like a double apron, but which, rather, is a 

 pouch. The hand may now be carried in either 

 lateral direction until it is arrested by the sides 

 of the pouch, which correspond, on the right 

 with the point where the colon crosses the duo- 

 denum, and on the left with the point where 

 the colon, from being transverse, becomes de- 

 scending, that is to say, the sides of the pouch 

 hang down from these points. Above the latter 

 point, the hand may be carried towards the left, 

 beyond the fundus of the stomach and some- 

 what behind the spleen, where it will be arrested 

 by an attachment to the posterior parietes, the 

 line of which extends from the cardia to the left 

 bend of the colon. 



There is, therefore, a great pouch of perito- 

 neum, the inside and outside of which are both 

 free ; and consequently it has an internal or 

 lining layer and an external layer; we will 

 presently show how these are continuous with 

 each other and with the peritoneal investments 

 of surrounding parts. The left side of the 

 mouth of this pouch is carried up into a long 

 corner reaching the cardia ; its continuous line 

 of attachment extends from the cardia along the 

 greater curvature of the stomach to the pylorus ; 

 then along a small extent of the duodenum till 

 it reaches the transverse colon ; next along the 

 transverse colon to its left bend, and thence 

 along on the posterior abdominal parietes of the 

 left hypochondriac region, or rather over the 

 left kidney, to the cardia whence we started. 

 The spleen is sessile upon the external surface 

 of this bag to the left of the fundus of the sto- 

 mach. That portion of it which intervenes 

 between the stomach and colon is called the 

 great omentum, and that portion which is 

 situated to the left of the fundus of the stomach 

 is called the splenic omentum. 



We may now return to our demonstration of 

 the continuity of the peritoneum by tracing its 

 free surface as before. The two surfaces or 

 layers of the lesser omentum were seen to be 

 continuous around the vessels enclosed in its 

 free right border, at the foramen of Winslow. 

 These two layers, as yet adherent, separate at 

 the lesser gastric curvature, invest the stomach 

 one behind and the other in the front meet 

 again, and again adhere along the fundus and 

 greater curvature, forming a sheet with two free 

 surfaces, which to the right extends to the spleen 

 and abdominal parietes. and downwards to the 

 transverse colon ; that part of it, however, which 

 intervenes between the stomach and colon is 

 bagged out or excessively widened so as, in 

 ordinary circumstances, to hang down in a 

 pouch as low as the pelvis. Having reached 

 the front of the transverse colon, the layers again 

 separate to invest it one above and the other 

 below meet again on its posterior aspect, and 

 again adhering together form the transverse me- 

 socolon, which extends from the colon to the 

 posterior abdominal parietes, where having ar- 



