THE ARTERIES 403 



b. The right innominate artery has branches exactly 



corresponding to those of the left innominate. 



c. The dorsal aorta, which is rather smaller than 



either of the innominate arteries, arches over to 

 the right side, crosses the right pulmonary artery, 

 and then runs backwards along the mid-dorsal 

 line of the thorax and abdomen. Its principal 

 branches are as follows. 



i. The coeliac artery is a median vessel which arises 

 about the level of the auriculo-ventricular 

 septum of the heart. It runs back in the 

 mesentery, and divides into branches which 

 supply the stomach, gizzard, and part of the 

 intestine. 



ii. The anterior mesenteric artery is a median 

 vessel, which arises about a quarter of an inch 

 behind the coeliac artery, and runs backwards 

 in the mesentery, dividing into branches 

 which supply the greater part of the length of 

 the intestine. 



iii. The anterior renal arteries are a pair of small 

 vessels, which arise from the aorta opposite 

 the anterior ends of the kidneys, and supply 

 their anterior lobes. From the artery of the 

 left side a branch is given off to the ovary. 



iv. The femoral arteries are paired, and arise 

 opposite the anterior lobes of the kidneys. 

 They pass outwards, dorsal to the kidneys, to 

 supply the extensor muscles of the thigh. 

 Each gives off a pubic artery, which runs 

 backwards along the ventral border of the 

 pubes. 



v. The sciatic arteries are a pair of larger vessels, 

 which arise opposite the middle lobes of the 

 kidneys : they pass outwards and backwards, 

 between the middle and posterior lobes of the 

 kidneys, and through the ilio-sciatic foramina, 



D D 2 



