500 FORAMEN OF WINSLOW OMENTUM. 



Hepatic artery, Hepatic plexus of nerves, 



Ductus communis choledochus, Lymphatics. 



Portal vein, 



These structures are enclosed in a loose areolar tissue, called Glisson's 

 capsule* The relative position of the three vessels is, the artery to the 

 left, the duct to the right, and the vein between and behind. 



If the finger be introduced behind this right border of the lesser omentum, 

 it will be situated in an opening called the foramen of Winslow. \ lu front 

 of the finger will lie the right border of the lesser omentum ; behind it the 

 diaphragm, covered by the ascending or posterior layer of the peritoneum ; 

 below, the hepatic artery, curving forwards from the cceliac axis ; and 

 above , the lobus Spigelii. These, therefore, are the boundaries of the fo- 

 ramen of Winslow, which is nothing more than a constriction of the gene- 

 ral cavity of the peritoneum at this point, arising out of the necessity for 

 the hepatic and gastric arteries to pass forwards from the cceliac axis to 

 reach their respective viscera. 



If air be blown through the foramen of Winslow, it will descend behind 

 the lesser omentum and stomach to the space between the descending and 

 ascending pair of layers, forming the great omentum. This is sometimes 

 called the lesser cavity of the peritoneum, and that external to the foramen 

 the greater cavity ; in which case the foramen is considered as the means 

 of communication between the two. There is a great objection to this 

 division, as it might lead the inexperienced to believe that there were 

 really two cavities. There is but one only, the foramen of Winslow being 

 merely a constriction of that one, to facilitate the communication between 

 the nutrient arteries and the viscera of the upper part of the abdomen. 



The Great omentum consists of four layers of peritoneum, the two 

 which descend from the stomach, and the same two, returning upon them- 

 selves to the transverse colon. A quantity of adipose substance is depo- 

 sited around the vessels which ramify through its structure. It would 

 appear to perform a double function in the economy. 1st. Protecting the 

 intestines from cold ; and, 2dly. Facilitating the movement of the intes- 

 tines upon each other during their vermicular action. 



The Transverse meso-colon (pffo$, middle, being attached to the middle 

 of the cylinder of the intestine) is the medium of connexion between the 

 transverse colon and the posterior wall of the abdomen. It also affords to 

 the nutrient arteries a passage to reach the intestine, and encloses between 

 its layers, at the posterior part, the transverse portion of the duodenum. 



The Mesentery (fxsVov IWs^ov, being connected to the middle of the cylin- 

 der of the small intestine) is the medium of connexion between the small 

 intestines and the posterior wall" of the abdomen. It is oblique in its di- 

 rection, being attached to the posterior wall, from the left side of the second 

 lumbar vertebra to the right iliac fossa. It retains the small intestines in 

 their places, and gives passage to the mesenteric arteries, veins, nerves, 

 and lymphatics. 



The Meso-rectum, in like manner, retains the rectum in connexion with 

 the front of the sacrum. Besides this, there are some minor folds in the 



Francis Glisson, Professor of Medicine in the University of Cambridge. His work, 

 " De Anatomia Hepatis," was published in 1654. 



t Jacob Benignus Winslow : his " Exposition Anatomique de la Structure du Corp, 

 Uumaiir" was published in Paris in 1732. 



