BRANCHES OF THE ABDOMINAL AORTA. 227 



nistra Inferior) goes towards the middle of the sigmoid flex- 

 ure of the colon, and there, like the preceding, divides into two 

 branches; one anastomoses with the artery above, while/ Jthe 

 other joins with the arteries which go to the rectum from the 

 inferior mesenteric. 



The Superior Ha3morrhoidal Artery (*ftrt. Hsemorrhoidea 

 Superior, fnterna,) is the lowest and the last branch of the 

 inferior mesenteric. It descends between the laminae of the 

 mesorectum, and is divided into two symmetrical trunks, which 

 radiate by dividing and subdividing on the side of the rec- 

 tum, and are dispersed in very fine and numerous branches 

 throughout its substance; and anastomose with the middle 

 and the inferior hsemorrhoidal arteries, also with the lateral 

 sacral. 



The Capsular Arteries (JirL Capsitlares) arise frequently from 

 the aorta just below the superior mesenteric; but quite as often, 

 if not more so, from the emulgents. They are not larger than 

 a crow's quill, and vary from one to three on either side, gene- 

 rally, however, not exceeding one : when they do, they are pro- 

 portionably small. Passing horizontally outwards, they divide 

 into several small ramifications, which terminate in the capsulae 

 renales. Some of their branches go to the lesser muscle of the 

 diaphragm. 



The Emulgent Arteries (*2rt. Emu/gentes, Renales,) are two 

 in number, one for each kidney, but sometimes more. They 

 are large and short, arise from the side of the aorta immediate- 

 ly below the superior mesenteric, and pass outwardly in a hori- 

 zontal direction. The right one is longer than the left, some- 

 what lower down, and passes behind the ascending cava. They 

 are both, in their course, from the aorta to the kidney, covered 

 in front by the emulgent vein, and have to pass through a mass 

 of adipose matter. 



The emulgent sends off some fine ramifications to the adipose 

 matter, which surrounds it, and before it reaches the fissure of 

 the kidney divides into three or four branches, preparatory to 

 its introduction into this gland, upon the structure of which it is 

 ultimately distributed by very fine branches. 



