288 SUPERIOR MESENTERIC ARTERY. 



of the stomach. It is situated between the lamina of the ante- 

 rior portion of the omentum. It sends some small branches to 

 the omentum, and others which are larger and more numerous, 

 to both sides of the stomach. Some of these last mentioned 

 anastomose with the ramifications of the gastrica dextra which 

 come from the hepatic. 



When the Splenic artery approaches near to the spleen, it 

 divides into four, five, or six branches, each of which pene- 

 trates into that viscus by a distinct foramen, and then ramifies 

 in the manner described in the account of the structure of the 

 spleen.* 



Either from the splenic artery, or from these ramifications, 

 four or five branches pass to the large extremity of the stomach 

 and ramify there, communicating with the vessels already 

 described. These arteries have received great attention from 

 physiologists, and are denominated Vasa Brevia. 



The Superior Mesenteric, 



Which is the second great branch given off in the abdomen 

 by the aorta, is not very different in size from the coeliac, and 

 originates about half an inch below it. It is distributed to the 

 small intestines ; to that portion of the great intestine which is 

 situated on the right side of the abdomen ; and to the arch of 

 the colon. From its origin it proceeds downwards, under the 

 pancreas, and over the lower portion of the duodenum, to 

 the commencement of the mesentery. When it has arrived 

 between the lamina of that membrane, it descends in a direction 

 which corresponds with that of the root of the mesentery ,f and 

 forms a gentle curve, with its convexity directed towards the 

 intestines. It necessarily diminishes as it ascends, and gene- 

 rally terminates by anastomosing with one of its own branches. 

 This great artery sends off some very small ramifications to the 

 pancreas and the duodenum, while it is in their vicinity. It 

 also sends two or three branches to -the transverse part of the 



* It frequently happens that the splenic artery divides only into two or three 

 branches, and they subdivide so as to form five or six, which penetrate the 

 spleen. 



f Vol. ii. p. 110. 



