466 ANATOMY IN A NUTSHELL. 



The peritoneum (literal meaning is stretched around) in the male forms a 

 closed sac. Ln the female it tonus an open sac by means of the two Fallopian 

 tubes. It has an outer or parietal layer and an inner or visceral layer. It 

 lines mos1 of the viscera of the abdominal cavity and in its development forms 

 folds and ligaments. The lesser sac is in the greater omentum but the greater 

 sac is not in the lesser omentum. A fold of peritoneum going from the abdom- 

 inal wall to the small intestine is called the mesentery. A fold of peritoneum 

 going from the lesser curvature of the stomach to the transverse fissure of the 

 liver is called the lesser omentum and a fold of peritoneum going from the greater 

 curvature of the stomach to the transverse colon is called the greater omentum. 



The greater omentum has four layers in it which cannot be demonstrated 

 in the adult but can be in the fetus. The lesser omentum has two folds in it. A 

 fold of peritoneum passing from the liver to the spleen is called gastro-splenie 

 omentum. All other folds of peritoneum are called ligaments. 



The following eleven structures are entirely covered with peritoneum: 

 (1) Spleen, (2) liver. (3) stomach, (4) first portion of the duodenum, (5) 

 small intestine, (6) csecum, (7) transverse colon, (8) sigmoid flexure, (9) first 

 portion of the rectum, (10) ovaries, and (11) the uterus. 



The following six structures are entirely stripped of peritoneum, (1) pan- 

 creas, (2) kidney. (3) suprarenal capsule, (4) third portion of the rectum. (5) 

 anterior portion of the bladder, and (6) lower portion of the vagina. 



Tracing the greater sac, (Plate CLI.) starting at the umbilicus and de- 

 scending, it covers the anterior abdominal wall, reflected over the symphysis 

 pubis, over the posterior portion of the bladder, overthe uterus and the anterior 

 surface of the rectum, forming a pouch called the pouch of Douglas, up the pos- 

 terior abdominal wall it reaches almost to the pancreas and there it is reflected 

 towards the small intestine forming the posterior layer of the mesentery; sur- 

 rounding the small intestine il passes up to the abdominal wall again, forming 

 the anterior laverof the mesentery and thereit is reflected over to the transverse 

 colon, forming the posterior layer of the transverse meso-colon; from there ii 

 forms the fourth and first layers of the greater omentum, passing up to the stomach 

 ami from there over the anterior border of the stomach and continuing up to 

 the transverse fissure of the liver forming the anterior layer of the lesser omentum. 

 From this fissure ii continues over the anterior portion of the liver, forming 

 the suspensory ligament of the Liver, from there being reflected on the anterior 

 abdominal wall down to the starting point. 



The lesser sac (Plate CLI) is traced from the posterior surface of 

 the liver, descending and forming the posterior layer of the lesser omentum. 

 being reflected over the posterior surface of the stomach and from there form- 

 ing the second and third Layersof the greater omentum and from there ascend- 

 ing and forming tli<' anterior laverof the transverse meso-colon up to the pos- 

 terior surface of the liver. 



The peritoneum can be shown as a closed sac best by a transverse section 

 at the umbilicus! (Plate CL.) 



The functions of the peritoneum are as follows: (1) It secrets serum which 

 Lubricates its adjacent surfaces. (2) it absorbs any excess of its own secretion 





