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 reaches them as mesentery, &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 in vested with peritoneu m 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 coverinp.,, 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 covering around 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.
The peritoneum passes over the anterior sur face of the kidneys and suprarenal capsules, but is not usually in immediate contact with them ; a. larg,e quantity of loose areolar and adipose tissue being interposed.
The jdunurn and ilium have a complete in vestment of peritoneum, except along the little linear space where the mesentery is attached to them.
The cercum and the ascending and descending colon are always invested with a peritoneal coat in front, and this extends to a variable distance around their sides, sometimes completely cover ing them except at the Iittle posterior linear spaces where their respective mesenteries, in such cases existing, are attached to them.
2'he transverse portion of the colon is com pletely covered by peritoneum except along two little linear spaces on the opposite sides of it, namely, on its anterior and posterior aspects, where the great omentum and transverse meso colon respectively, as described above, are attached.
2'he sigmnidjlexure of the colon and the first portion of the rectum are invested completely with peritoneum, except along the line of at tachment of their respective mesenteries.
The second portion of the rectum has a peri toneal investment on its front only : its lateral and posterior aspects are destitute of such co vering. The peritoneum, as above stated, passes across from the rectum to the bladder without descending low enough to afford any investment whatever to the lowermost or third portion of the rectum. The conventional divi sion of the rectum into three portions is, in fact, founded upon this circumstance of its being first completely, then partially, and lastly not at all invested with peritoneum, as you proceed from above downwards. The summits of the recto-vesical folds landmark the point of junction of the upper and middle portions.