THE ARTERIES. 



The terminal branches of the coeliac artery comport fliemselves as follows :— 



1. The superior artery of the omasum and abomasum passes successively to the great 

 curvature of the first of these reservoirs, and to the concave curvature of the second ; then it 

 goes beyond the pylorus to unite with the duodenal branch of the hepatic artery by inoscula- 

 tion (Fig. 367, 6). • 



2. The inferior artery of the omasuin and abomasum, on the contrary, passes at first over 

 the small curvature of the omasum, afterwards the great curvature of the abomasum, and 

 disappears in the omentum, to which on its course it furnishes a great number of branches 

 (Fig. 367, 7). 



In small Ruminants, the distribution of the arteries of the coeliac axis presents some 

 modifications. We will cite the principal, which belong to the mode of origin of the two 

 branches destined for the reticulum — these branches form two particular vessels which arise 



singly from the coeliiic axis : the 

 Fig. 367. inferior artery at the same point as 



. ; _ the superior artery of the rumen, the 



'*^°^^ superior towards the terminal bifur- 



cation of the axis. 



Anterior mesenteric artery. — Its 

 origin approaches very closely that 

 of the coeliac axis. After a course 

 of from 6 to 8 inches, it divides into 

 two branches — an anterior and a 

 posterior. The first, for the small 

 intestine, creeps above it, between 

 the two layers of the mesentery, and 

 passes backward by describing a 

 curve which gives off from its con- 

 vexity — that is, below — a great num- 

 ber of branches, analogous in their 

 mode of termination to the arteries 

 of the small intestine in the Horse. 

 The posterior branch goes to the 

 large intestine, where it separates 

 into two principal branches: one 

 wliich passes to the colon, its di- 

 visions crossing to the right, to be- 

 hind and below, the convolutions 

 described by that viscus; another 

 which reaches the concave curvature 

 of the caecum, and anastomoses by 

 an arch with the terminal extremity 

 of the parent-branch of the arteries 

 supplying tlie small intestine. 



Posterior mesenteric artery. — Very 

 short and narrow. 

 Renal, spermatic, and small spermatic arteries. — These do not differ in their essential 

 disposition from the analogous vessels in Solipeds. 



2. Posterior Aorta in the Pig. 

 With the exception of the mesenteric vessels, the distribution of which resembles that 

 already indicated for Ruminants, and with the exception, also, of the middle sacral artery, 

 which will be alluded to when describing the internal iliac arteries, all the branches given off 

 by the posterior aorta comport themselves almost as in the Horse. 



3. Posterior Aorta in Carnivora. 



In these animals, as well as in the Pig, the denomination of posterior aorta is not justifiable, 

 because the arteries of the head and thoracic limbs spring directly from the aortic arch. 



The branches of the aorta are distinguished as parietal and visceral. 



A. Parietal Branches. — Beyond the fourth space, the intercostal arteries are furnished 

 by the aorta ; the first is voluminous, and throws off some considerable filaments to the musclee 

 of the withers. The first two lumbar arteries arise from the thoracic portion of the aorta, 

 because of the very backward insertion of the diaphragm ; the third is detached between the 



arteries of the stomach in ruminants. 

 1, Coeliac axis ; 2, superior artery of the rumen ; 3, 

 inferior artery of the rumen ; 4, inferior artery of the 

 reticulum ; 5, superior artery of the reticulum ; 6, 

 superior artery of the omasum and abomasum ; 7, 

 inferior artery of ditto ; 8, splenic artery. A, 

 (Esophagus; b, left sac of the rumen; b', left conical 

 vesica; c, right sac of the rumen; c', right conical 

 vesica ; D, reticulum ; e, omasum ; F, abomasum ; G, 

 duodenum ; R, spleen. 



