THE PERITONEUM. 



1747 



Diagram showing later stage where secondary mesentery is formed and 

 duodenum (D) and colons (C C) lie against posterior body-wall. The ad- 

 ditional colors indicate the fusion of the original parietal and-visceral perito- 

 neum, purple from the blue with the red, green from the blue with the yellow. 



manent serous covering of the posterior abdominal wall, which here is that of the 

 original right side of the mesogastrium. The spleen, and perhaps the tail of the 

 pancreas, lie free, surrounded by peritoneum. If the hand be introduced into the 

 left hypochondrium, it slides along the wall behind the spleen to the point at which 



the splenic vessels leave the 

 Fig. 1472. posterior wall and pass in 



a fold, the lieno-retial liga- 

 ment, to the hilum of the 

 spleen. From this position 

 the hand can be carried 

 around the spleen to the 

 front of the vessels at the 

 hilum and thence to the 

 right along the continua- 

 tion of the mesogastrium to 

 the greater curvature of the 

 stomach, where its layers 

 separate to coat the front 

 and back of that organ. 

 The part of the mesogas- 

 trium between the stomach 

 and the spleen is th& gastro- 

 sple7iic omentum. The right 

 layer of peritoneum of the 

 mesogastrium, lining first 

 the hind wall of the abdo- 

 men and then the back of the stomach, bounds the lesser cavity of the peritoneum. 

 The gastro-phrenic ligament is a small vertical fold, usually found extending from 

 the left of the end of the oesophagus to the top of the stomach. Near it is often 

 another, the suspensory Iigat7ie7it of the spleen, extending from the diaphragm to 

 the top of that organ, of which it may enclose a small part. It marks the upper 

 part of the line of reflection of the mesogastrium from the posterior abdominal wall. 

 The phreyio-colic fold, also derived from the mesogastrium, is a horizontal shelf 

 with a free anterior semi- 

 lunar edge forming the floor Fig 

 of a niche for the spleen. 

 It extends from about the 

 eleventh rib inward onto the 

 upper surface of the trans- 

 verse colon. That this liga- 

 ment is really a part of the 

 mesogastrium, and not a lig- 

 ament of the colon, is shown 

 by development, as well by 

 its existence (as in the mon- 

 key) when the descending 

 colon is unattached to the 

 wall. 



The Greater Omentian. 

 — We are now to trace the 

 mesogastrium in a sagittal 

 plane downward from the 

 greater curvature of the 

 stomach. On opening the 

 abdomen the first thing that 

 appears below the stomach is \h^ greater omentum (omentum majus), which is 

 spread like an apron over the intestines. It is that part of the mesogastrium 

 which is situated in front. The terms gastro-colic and gastro- splenic omenta 

 are but names for different parts of this structure. It extends from the greater 



Diagrammatic section passing through level of foramen of Winslow, 

 showing relations of parietal and visceral peritoneum within lesser sac 

 {LS)\ GH, cut gastro-hepatic omentum, containing portal vein (P), he- 

 patic artery (//),and bile-duct {B); Si. stomach ; GS. gastro-splenic omen- 

 tum ; LP, lieno-renal ligament ; FC, A, vena cava and aorta. 



