PERITONEUM. 



943 



passage to the transverse portion of the duo- 

 denum. 



The mesentery is the peritoneal fold that 

 connects the small intestine to the posterior 

 abdominal parietes, giving transit to the vessels 

 and nerves of that part of the intestinal tube. 

 Numerous lymphatic glands, called mesenteric 

 glands, are also included between its layers. It 

 is eight inches in breadth at ils widest part, and 

 narrows off towards each end, where the small 

 intestine becomes adherent to the parietes. Its 

 parietal attachment, as mentioned above, is 

 only a few inches in extent, whilst its visceral 

 border is usually twenty feet long. 



The ascending mesocolon, descending meso- 

 colon, and mesoceecum, when they exist, and the 

 iliac or sigmoideal mesocolon and mesorcctum, 

 which always exist, perform all the ofh'ces of 

 mesenteries to those parts, respectively, of the 

 intestinal tube which are indicated in their 

 names. 



The appendices epiploica; are numerous small 

 masses of fat, somewhat pyriform, and having a 

 peritoneal investment, attached along the large 

 intestine. Their use is not known ; perhaps 

 they serve as packing to the sacculated bowel 

 on which they are placed. 



The recto-vesical folds give transit to some 

 vesical vessels and the umbilical arteries of the 

 foetus. The cellular tissue enclosed by them is 

 very lax, so that they are easily unfolded by 

 distention of the bladder. 



Tlie broad ligaments of the. uterus are two 

 folds of peritoneum passing from the lateral 

 borders of the uterus to the opposite abdominal 

 parietes. The line of their summits is about 

 level with that of the superior border of the 

 unimpregnated uterus. This summit or supe- 

 rior border of the broad ligament is defined by 

 the Fallopian tube which it encloses ; a little 

 lower down on its posterior aspect the ovary is 

 sessile upon it, invested in a secondary fold of 

 its posterior layer : and the round ligament of 

 the uterus passing between its layers from the 

 side of the uterus to the inguinal canal carries 

 out another little secondary fold in front of it. 

 The broad ligament, then, and its secondary 

 folds, enclose the ovary with its ligament, the 

 Fallopian tube, the round ligament of the ute- 

 rus, and the spermatic vessels and nerves. The 

 layers of the broad ligament itself, but not those 

 of its secondary folds, are connected together 

 by loose areolar tissue, and are separated (the 

 broad ligament itself becoming effaced) by the 

 enlargement of the uterus in pregnancy. 



There are a pair of recto-uterine peritoneal 

 folds in the female and a pair of vesico-uterine 

 folds ; the former pass across from the sides of 

 the rectum to the sides of the uterus, and repre- 

 sent the recto-vesical folds of the male ; the 

 latter pass across from the sides of the uterus 

 to the sides of the bladder. The layers of both 

 pairs are very loosely connected together. 



There is a slight median fold and two slight 

 lateral folds of the peritoneum lining the ante- 

 rior abdominal parietes, converging from the 

 fundus and sides of the bladder to the navel ; 

 they enclose the remains of the urachus and of 

 the two umbilical arteries of the fail us. 



At the point corresponding with each inter- 

 nal abdominal ring in the male subject, there 

 is a little infundibuliform depression or dimple 

 of the peritoneal surface ; it indicates the point 

 from which a portion of peritoneum, being car- 

 ried down with the testicle in its descent, was 

 separated to form the tunica vaginalis in the 

 female; from the same points a cylindrical 

 sheath of peritoneum accompanies the round 

 ligament a little way into the inguinal canal; 

 this sheath has been called the canal of Nuck. 



With regard to our third proposition, THE 



SEROUS COAT AFFORDED BY THE PERITONEUM 



TO THE VARIOUS VISCERA invests some of them 

 completely, except along little linear spaces, 

 imaginary rather than real, where it readies 

 them as rnesentery, &c. : others it invests on 

 one side only, and others again still more par- 

 tially. 



The liver has an investment of peritoneum 

 complete, except at its posterior, thick, rounded 

 border, over a space of inconstant form be- 

 tween the anterior and posterior layers of the 

 coronary ligament, where the liver is in imme- 

 diate contact with the diaphragm, the space 

 corresponding with the gall-bladder, and along 

 the little linear spaces where the falciform and 

 triangular ligaments and the lesser omentum 

 are attached to it. 



The gall-bladder is invested with peritoneum 

 on its lower aspect only ; that side which is 

 presented towards the liver is in immediate 

 contact with it. 



The. stomach is completely invested with pe- 

 ritoneum, except at the two little linear spaces 

 along its curvatures, where the lesser and greater 

 omenta are attached to it. 



The spleen is invested by the peritoneum 

 completely, except at its hilus, where its vessels 

 enter from the omentum. 



The first or ascending portion of the duode- 

 num has a complete peritoneal investment, 

 except at a little linear space along its lower 

 aspect, where the great omentum is attached to 

 it, so that this portion is free to move. The 

 second, or descending portion has peritoneal 

 investment on its anterior aspect only. The 

 third or transverse portion is invested with pe- 

 ritoneum along a very narrow portion of the 

 upper, and a somewhat less narrow portion of 

 the lower part of its anterior aspect ; the whole 

 of its posterior aspect and the middle part of 

 its anterior are destitute of peritoneal covering', 

 the former being adherent to the posterior abdo- 

 minal parietes, &c., the latter corresponding 

 with the root of the transverse mesocolon. Its 

 upper aspect is adherent to the pancreas, which 

 encroaches upon the upper one of the two 

 spaces mentioned as invested with peritoneum. 

 At the point where the duodenum is crossed by 

 the colon, which is just where from descending 

 it becomes transverse, the two bowels are in 

 immediate contact, so that the duodenum is, at 

 this point, destitute of peritoneal coveringaround 

 its entire circumference. Where the superior 

 mesenteric artery crosses the duodenum, the 

 peritoneum is borne off from it by that vessel. 



The pancreas is invested with peritoneum on 

 its anterior surface only. 



