and their Relation to the Peritoneum. 



477 



discussed before,* so that it does not seem necessary to do more than 

 allude to them briefly. Stated as shortly as possible, it may be said 

 that at the oesophageal and pyloric ends of the stomach the mesOgas- 

 trium remains short, but near the middle elongates and becomes the 

 great omentum. This anomalous structure afterwards enters into 

 relation with the transverse colon; but at present the manner in 

 which this is brought about need not be discussed. 



This much having been premised, it may be inquired whether these 

 observations are applicable to the adult subject. The mesogastrium 

 having been identified with the great omentum, it remains to be seen 

 if the blood supply of the stomach still passes through it. The 

 gastric artery certainly conforms to the conditions. This artery 

 begins behind the peritoneum, and runs between two layers of this 

 membrane to reach the oesophageal end of the stomach. These folds of 

 peritoneum represent the upper part of the mesogastrium, and are 

 continuous below with the great omentum. To confirm these state- 

 ments the lesser sac of the peritoneum should be opened ; a hand 

 passed within it towards the right of the oesophagus enters the con- 

 cavity of a loop which the gastric artery makes ; a hand introduced 

 into the greater sac, to the left of the oesophagus, touches the con- 

 vexity of the loop. When the anatomy of the gastric artery is com- 

 pared with the original vessels of the mesentery its close resemblance 

 to them is clear; the modifications which have occurred are com- 

 paratively insignificant. As it has been explained how the meso- 

 gastrium forms the left boundary of the lesser peritoneal cavity, it 

 therefore seems unnecessary to enter into details concerning the 

 relations of the vessels which it contains to the greater and lesser 

 sacs. 



If the arteries of the stomach were taken in detail the vasa brevia 

 would come next, and afterwards those near the pylorus. Passing 

 over the vasa brevia, for the moment, the following question seems to 

 demand an answer. If the mesogastrium originally contained nume- 

 rous vessels, how is it that, with the exception of the vasa brevia, none 

 are found between the oesophagus and pylorus ? Generally speaking, 

 structures receive their blood supply by the nearest route, and 

 exceptions to this rule can usually be accounted for. The elongation 

 of the mesogastrium, to form the great omentum, is so excessive that 

 it might almost be anticipated that none of its vessels would persist. 

 Whatever the probabilities may seem, it has always been recognised 

 that the omentum contains enormously long vascular loops, which 

 extend from the curve of the stomach to the transverse colon ; they 

 are usually spoken of as being the longest arterial loops in the body. 

 Although these vessels appear to be more for the supply of the 



* "On the Development of the Great Omentum and Transverse Meso-colon," By 

 C. B. Lockwood, " Proc. Roy. Soc.," vol. 35, p. 279. 



