THE EXTERNAL OR ADIIERENT SURFACE OP TIIE PERITONEUM is attached to the apposed tissues with different degrees of intimacy in different situations--a circumstance of great importance with regard to certain surgical operations. This attachment is intimate or otherwise, according as the areolar tissue that constitutes the connecting medium is abundant or scarce, loose or compact, in different situa tions. The connecting areolar tissue is con tinuous through the openings in the abdominal parietes with the other areolar sheets of the body. The parietal portion of the peritoneum is strengthened by a fibrous layer, so that abscesses seldom burst through it; whilst the visceral portion, being destitute of this layer, is not unfrequently burst through by abscesses of an abdominal viscus, as the liver. The peritoneum lining the under surface of the diaphragm is the most firmly attached of all the parietal portion. That which lines the anterior abdominal parietes is very intimately adherent along the linea alba and sheath of the rectus, but very loosely just above the pubis and about the internal abdominal ring. It is extremely loosely attached to the posterior abdominal parietes and immediately superjacent organs, and in the lumbar and pelvic regions and iliac fossm—a very fortunate circumstance with regard to placing ligatures on the large abdominal and pelvic vessels without laying open the peritoneal cavity.
The visceral portion, as it covers the liver and spleen and the alimentary tube, is very intimately adherent to them except at the middle poition of the rectum. That which partially covers the bladder adheres very loosely to it; owing to which, together with the loose ness of the peritoneal attachment above the pubis in front, to the rectum behind, and to itself in the recto-vesical folds, the bladder when distended rises high above the pubis between the abdominal parietes and perito neum, pushing the latter up so as to diminish the depth of the recto-vesical cul-de-sac and leave its inferior fundus uncovered by it ; con sequently the bladder when distended may be punctured above the pubis or through the rectum without injuring the peritoneum.
In the mesenteries, omenta, and other peri toneal duplicatures, where the external surface of the peritoneum adheres to itself, the adhesion is generally extremely intimate. They are most separated where deposits of fat have taken place between them. The recto-vesical folds and the broad ligaments of the uterus alone, of all the peritoneal duplicatures, have their layers loosely adherent.
The peritoneum is very frequently the seat of extensive inflammation, the lymph effused in which process, besides causing adhesions of the abdominal viscera to one another and to the parietes, frequently covers the free peri toneal surface with a thick adherent layer or false membrane; and this, like some other tissues formed from lymph, shrinks or cicatrizes in every direction, and thereby produces sorne very curious secondary effects. In such cases, if the great omentum is free at its lower border, it becomes tucked up to the greater convexity of the stomach and apparently obliterated; or if adherent, as to a hernial sac, the shrinking of the new tissue that covers it drags down the stomach. The thin sharp edges of the liver become rounded by this agent, and the calibre of the intestinal tube diminished; sometimes the intestine is even strictured by the contrac tion of an unusually large deposit at a par ticular part. The tendency of this tissue to shrink, however, being controllable by suffi cient mechanical resistance is most manifest in those directions in which' it experiences no such opposition; for which reason it tells more on die length than on the circumference of an intestine, and Cruveilhier met with a case of chronic peritonitis in which the small intestine measured only seven feet in length. If the hand is placed on the belly of a person in whom this condition exists, the muscles are felt to glide loosely over the peritoneum ren dered tense beneath them.
For the minute anatomy of the peritoneum see SEROITS MEMBRANE.
( Simon Rood Pittard.)