THE PERITONEUM. 899 



is also reflected from the sides of the uterus to the lateral walls of the pelvis as two 

 expanded folds, the broad ligaments of the uterus, in the free margin of each of 

 which can be felt a thickened cord-like structure, the Fallopian tube. 



On following the parietal peritoneum upward on the back of the anterior 

 abdominal wall it is seen to be reflected around a fibrous band, the lig amentum 

 teres or obliterated umbilical vein, which reaches from the umbilicus to the under 

 surface of the liver. Here the membrane forms a somewhat triangular fold, the 

 falciform or suspensory ligament of the liver, which attaches the upper and anterior 

 surfaces of that organ to the Diaphragm and abdominal wall. With the exception 

 of the line of attachment of this ligament the peritoneum covers the under surface 

 of the anterior part of the Diaphragm and is reflected from it on to the upper 

 surface of the liver as the anterior or superior layer of the coronary ligament. 

 Covering the upper and anterior surfaces of the liver it is reflected round its sharp 

 margin on to its under surface as far as the transverse fissure, where it is continuous 

 with the anterior layer of the small omentum from which a start was made. The 

 posterior layer of this omentum is carried backward from the transverse fissure over 

 the under surface and Spigelian lobe of the liver, and is then reflected, as the pos- 

 terior or inferior layer of the coronary ligament, on to the Diaphragm and is pro- 

 longed downward over the pancreas to become continuous with the ascending layer 

 of the transverse mesocolon. Between the two layers of the coronary ligament 

 there is a triangular surface of the liver which is devoid of peritoneum ; it is 

 named the bare area of the liver, and is attached to the Diaphragm by connective 

 tissue. If, however, the two layers of the coronary ligaments are traced toward 

 the right and left margins of the liver, they approach each other, and, ultimately 

 fusing, they form the right and left lateral ligaments of the liver and attach its 

 right and left lobes respectively to the Diaphragm. 



If the small omentum is followed toward the right side it is seen to form a 

 distinct free edge around which its anterior and posterior layers are continuous with 

 each other and between which are situated the portal vein, hepatic artery, and bile- 

 duct. If the finger is introduced behind this free edge, it passes through a some- 

 what constricted ring, the foramen of Window. This is the communication 

 between what are termed the greater and lesser sacs of the peritoneum and has the 

 folloAving boundaries: in front, the free edge of the gastro-hepatic omentum with 

 the portal vein, hepatic artery, and bile-duct between its two layers ; behind, the 

 vena cava inferior ; above, the Spigelian and caudate lobes of the liver ; below, 

 the duodenum and the hepatic artery, as the latter passes forward and upward 

 from the coeliac axis. 



The lesser sac of the peritoneum therefore lies behind the small omentum and 

 has the following dimensions : above, it is limited by the portion of the liver which 

 lies behind the transverse fissure ; below, it extends downward into the great omen- 

 tum, reaching, in the foetus, as far as its free edge ; in the adult, however, its verti- 

 cal extent is limited by adhesions between the layers of the omentum. In front, it 

 is bounded by the small omentum, stomach, and anterior two layers of the great 

 omentum ; behind, by the two posterior layers of the great omentum, the trans- 

 verse colon, and ascending layer of the transverse mesocolon which passes upward 

 in front of the pancreas as far as the posterior surface of the liver. Laterally the 

 lesser sac reaches from the foramen of Winslow on the right side as far as the 

 spleen on the left, where it is limited by the lieno-renal ligament. The extent of 

 the lesser sac and its relations to surrounding parts can be definitely made out by 

 tearing through the small omentum atid inserting the hand through the opening 

 thus made. 



It should be stated that during a considerable part of foetal life the transverse 

 colon is suspended from the posterior abdominal wall by a mesentery of its own 

 the two posterior layers of the great omentum passing, at this stage, in front of 

 the colon. This condition sometimes persists throughout adult life, but as a rule 

 adhesion occurs between the mesentery and the transverse colon and the posterior 

 layer of the great omentum, with the result that the colon appears to receive 



