512 A MANUAL OF ANATOMY. 



q. v. above, (ti) From the convex side the vasa intestini 

 tennis, 12 to 1 6 branches, are given off to supply the small 

 intestine from the last portion of the duodenum to within a 

 short distance from the caecum. These intestinal branches 

 form from three to five systems of arterial anastomoses 

 between their origin and distribution, (c) The ileocolic 

 supplies the last portion of the small intestine and the 

 beginning (caecum) of the large. It anastomoses on one 

 side with the last intestinal branch and on the other with 

 the (d) colica dextra. This artery is distributed to the 

 ascending colon. (<?) The colica media supplies the trans- 

 verse colon. These last three arteries form long arterial 

 arches from one to the other, and from the main arches 

 other secondary ones are formed before the intestine is 

 finally reached. A-long with the artery runs the vein, only 

 in the contrary direction, and at the right side of the artery. 

 The vein disappears under the pancreas, where it helps to 

 form the portal vein. See page 514. Its tributaries are 

 the right gastro-epiploic, pancreaticoduodenal (superior and 

 inferior), besides the veins corresponding to the branches of 

 the superior mesenteric artery. 



DISSECTION. 



Tie two strong strings around the small intestine six inches from the duo- 

 denum and the same distance from the caecum, divide the intestine between 

 the cords at both points, cut it away from its mesentery, and remove it entirely. 

 Clean the inferior mesenteric artery, tracing its branches to the descending 

 colon, omega loop, and rectum. 



The Inferior Mesenteric Artery. Figs. 102, 105. 



Is given off from the left side of the abdominal aorta 

 one and one-half inches above its bifurcation. 



Its Branches. 



(a) The colica sinistra supplies the descending colon. 

 (&) The sigmoid is distributed to the sigmoid, or omega 



