BRANCHES OF TBE AORTA ABDOMIXALIS. 359 



of the pylorus ; tlien it extends along the greater curvature of the stomach in the ventral 

 fold of the great omentum near its attachment to the stomach. It anastomoses with a 

 branch from the spleen (gastro-epiploiea sinistra ?) 



(3) A. pancreatico-duodenalis superior. — This passes along the dorsal side of the pylo- 

 rus, then to the left of the duodenum. It finally anastomoses with the pancreatico-duode- 

 nalis inferior (Fig. 81). 



(D) A. coronaria ventriculi, az. — This hranch arises from the coeliac axis only slightly 

 peripherad of the A. hepatica, and is distributed to the lesser curvature of tlie stomach. 

 One of its larger branches anastomoses with the A. pyloriea (§ 966, [1]). 



(E) AA. ventriculi dorsales (Chauveau, A, 559). — There are usually two of these. 

 They pass directly to the dorso-sinistral part of the stomach. Their homology is doubtful. 



(F) A. splenica, az. — This is the largest branch of the cceliac axis, and seems to he a 

 continuation of it. It passes to the spleen, hut before reaching that organ divides into 

 two nearly equal branches, one going to each extremity. 



The spleen is sometimes double, and in such a case each part is suppUed by one of the 

 branches just mentioned. 



Numerous small branches pass from the A. splenica to the pancreas and to the stomach. 

 One branch passes dextrad in the ventral fold of the great omentum to anastomose with 

 the A. gastro-epiploiea dextra (§ 966, [2]). This may be the homologue of the A. gastro- 

 epiploiea sinistra of man. It is small, and only rarely is the anastomosis shown with the 

 ordinary plaster injection. In fresh specimens the artery will contain sufficient blood to 

 enable one to trace it. It is of course easily filled with a fine injecting mass (§ 1450) 



§ 967. A. mesenterica superior — Superior mesenteric artery, az. 

 (Fig. 101, 103, 107). — Turn the stomach and intestines to the right. 

 The artery arises about 2 cm. caudad of the A. coeliaca. Expose it 

 fully by tearing away the peritoneum and nerves covering it. Use 

 the tracer, and the scissors occasionally if necessary. Observe the 

 following branches and their connections and distribution : — 



(A) A. pancreatico-duodenalis inferior (Fig. 81 [10]). — This passes obliquely cephalad 

 to the duodenal pancreas and anastomoses with the A. pancreatico-duodenalis superior. 



(B) A. colica media. — This branch is of considerable size. It passes to the large 

 intestine and sends branches cephalad and caudad. The cephalic branch anastomoses 

 with the A. colica dextra (C) or, if that is absent, with the A. ileo-colica. The caudal 

 branch anastomoses with the A. colica sinistra (§ 971, A). 



(C) A. colica dextra. — This is often absent in the cat. When present it passes to 

 the large intestine, and anastomoses with both (B) and (D). 



(D) A. ileo-colica. — This is a large branch, extending directly to the caecum. It sends 

 branches caudad to the large intestine, where they anastomose with (B) or (C), and others 

 cephalad to the ileum, where they anastomose with the Rami intestini tenuis. 



(E) Rami intestini tenuis. — These are the branches into which the A. mesenterica 

 superior finally breaks up, and, as the name indicates, they are distributed to the small 

 intestine. 



§ 968. A. adreno-lumbalis (Fig. 101, 103, 107).— This artery arises from the side of 

 the aorta, just caudad of the origin of the A. mesenterica superior (g 967). It passes 

 directly laterad, giving off the following branches : (A) the A. adrenalis to the adrenal, 

 and (B) the A. phrenica to the diaphragm. The artery rests on the free or ventral surface 



