3 2o ABDOMEN 



pancreatico-duodenal branch takes origin from the upper 

 part of the superior mesenteric artery, or from its first 

 intestinal branch, and passes upwards and to the right 

 behind the head of the pancreas. It gives branches both 

 to the duodenum and to the pancreas, and anastomoses with 

 the superior pancreatico-duodenal artery. 



Arterise Jejunales et Ilese. The jejunal and ileal branches 

 spring from the convexity or left side of the superior mesenteric, 

 and proceed obliquely downwards and to the left, between the 

 layers of the mesentery, to supply the jejunum and ileum. 

 They are very numerous from twelve to fifteen, or even more, 

 in number and, by the inosculations of their branches, they 

 form a very remarkable succession of arches between the 

 layers of the mesentery. At first they run parallel to one 

 another; but soon each divides into two branches which join 

 the immediately adjacent branches of the neighbouring stems, 

 and in that way a series of arterial arcades is formed. From 

 the primary arcades smaller vessels proceed, which divide and 

 unite, in a similar manner, to form a second series of arches ; 

 and so on, until three, four, or perhaps even five, tiers of 

 arterial arcades are produced. From the most peripheral 

 arches numerous small branches pass directly to the wall of 

 the intestine. At the intestine, along the line of mesenteric 

 attachment, they divide, and the minute twigs, thus derived, 

 pass transversely round the gut so as to encircle it. At first 

 they lie immediately subjacent to the peritoneal coat of the 

 bowel, but soon they seek a deeper plane in the wall of the 

 intestine, and ultimately after passing through the muscular 

 coats their terminal branches reach the submucous coat. 

 The number of arterial arcades which intervene between the 

 primary and terminal branches increases towards the lower 

 part of the small intestine (Fig. 148). 



Arteria Ileocolica. The ileo-colic artery springs from 

 the middle of the concavity of the superior mesenteric, and 

 proceeds downwards and laterally towards the right iliac fossa. 

 It is placed behind the parietal peritoneum, and divides into 

 an ascending and a descending or ileo-cascal branch. The 

 ascending branch turns upwards, inosculates with a branch of 

 the right colic, and from the arterial arch thus formed 

 branches are given to the ascending colon. The descending 

 branch, sometimes called the ileo-ccecal artery, proceeds to the 

 upper part of the ileo-caecal junction and sends branches in 



