INFERIOR MESENTERIC ARTERY. 289 



colon, to the right portion of the colon, to the beginning of the 

 great intestine, and the contiguous portion of the ileon. These 

 branches are commonly termed the Colica Media, Colicq Dex- 

 tra, and lleo Colica. From the convex side of the curve, the 

 superior mesenteric sends off the important branches which 

 pass between the lamina of the mesentery, and supply the 

 Small Intestines. These branches are numerous, and many of 

 their ramifications anastomose with each other, so as to form 

 arches. From these arches go off other branches, which anas- 

 tomose again with some of similar origin to form other arches, 

 which are much more numerous than the first set ; and 

 this process is repeated successively several times, so that a 

 net-work of blood-vessels seems to be formed on the mesentery. 

 From the mesentery the small ramifications are continued, in 

 great numbers, to the intestines. Some of them anastomose 

 with each other on the coats of the intestine ; but an immense 

 number of minute arteries are continued to the villous coat, so 

 that, when they are successfully injected, the surface of that 

 coat appears uniformly colored by the injection.* 



The Inferior Mesenteric Artery 



Does not go off from the aorta next in order after the superior 

 mesenteric, but succeeds it immediately on the intestines, and 

 continues the arterial ramifications to the left portion of the 

 colon, to which the branches of the superior mesenteric do not 

 extend. 



This artery arises between the origin of the emulgents and 

 the great bifurcation of the aorta, and proceeds downwards, 

 inclining to the left, but keeping near to the aorta. There are 

 generally three branches distributed to the left portion of the 

 colon, which arise from this artery, either separately, or by a 

 common trunk which soon divides. It frequently happens, that 

 one of these arteries arises separately, and two by a common 

 trunk. These are called the Left Colic arteries ; and are also 

 sometimes denominated, from their position, Superior, Middle, 



* See the account of the termination of these arteries, at page 46 of this 

 volume. 



VOL. ii. 25 



