SUPERIOR MESENTERIC ARTERY. 313 



tributed to the small intestine from the duodenum to the termination of the 

 ileum. In their course between the layers of the mesentery, they form a 

 series of arches by the inosculation of their larger branches ; from these 



Fig. 154.* 



are developed secondary arches, and from the latter a third series of arches, 

 from which the branches arise which are distributed to the coats of the in- 

 testine. From the middle branches a fourth and sometimes even a fifth 

 series of arches is produced. By means of these arches a direct commu- 

 nication is established between all the branches given off from the convex- 

 ity of the superior mesenteric artery ; the superior branches moreover sup- 

 ply the pancreas and duodenum, and inosculate with the pancreatico- 

 duodenalis ; and the inferior with the ileo-colica. 



The lleo-colic artery is the last branch given off from the concavity of 

 the superior mesenteric. It descends to the right iliac fossa, and divides 

 into branches which communicate and form arches, from which branches 

 are distributed to the termination of the ileum, the caecum, and the com- 

 mencement of the colon. This artery inosculates on the one hand with 

 the last branches of f * vasa intestini tenuis, and on the other with the last 

 colica dextra. 



* The course and distribution of the superior mesenteric artery. 1. The descending 

 portion of the duodenum. 2. The transverse portion. 3. The pancreas. 4. The jeju- 

 num. 5. The ileum. 6. The caecum, from which the appendix vermiformis is seen 

 projecting. 7. The ascending colon. 8. The transverse colon. 9. The commencement 

 of the'descending colon. 10. The superior mesenteric artery. 11. The colica media. 

 12. The branch which inosculates with the colica sinistra. 13. The branch of the supe- 

 rior mesenteric artery, which inosculates with the pancreatico-duodenalis. 14. The co 

 lica dextra. 15. The ileo-colica. 1G, 16. The branches from the convexity of the supe- 

 rior mesenteric to the small intestines. 



27 



