164 DISEASES OF THE DIGESTIVE APPARATUS. 



phragm, and also enteritis. The anti-peristaltic movements origin- 

 ating in the intestinal portion anterior to the paralyzed segment 

 sometimes fill the stomach to such an extent that it is almost burst- 

 ing; the abundant production of gas in the intestine may produce 

 tearing of the walls of this organ or of the diaphragm, through the 

 enormous pressure exerted upon it. 



The anatomical construction, especially of the anterior mesenteric 

 plexus singularly favors the development of embolic colics. This 

 artery issues from the posterior aorta in the shape of a large trunk 

 from ten to twelve centimetres in length ; immediately after its 

 origin it gives off — first, the superior colic artery ; secondly, pos- 

 terior and exactly opposite to the preceding, from seventeen to 

 twenty divisions to the small intestine. From this point the remain- 

 der of the vessel receives the name of ileo-csecal-colic artery, and 

 it is this which is ordinarily the seat of aneurism. The ileo-csecal- 

 colic artery is divided into four branches : the anterior, the largest ; 

 the inferior colic artery, which is the termination of the common 

 trunk ; then in succession are given off the superior caecal artery, 

 then the inferior, and lastly the ileo-caecal. 



As a general rule, the ileo-csecal-colic artery is not completely 

 obstructed by the aneurismal thrombus ; its four terminal brauches 

 still distribute the full amount of blood to those tissues into which 

 they ramify, so that no serious trouble is apparent. On the con- 

 trary, however, when the obstruction is complete, the caecum re- 

 ceives absolutely no blood ; this is not the case with the colon, 

 because of the anastomosis which exists between the superior "left'' 

 ;and the inferior "right" colic arteries. The obliteration of one of 

 these latter arteries cannot produce fatal thrombo-embolic colics ; 

 they are only both obliterated when the aneurism originates in the 

 great mesenteric. Then we may observe emboli in the small intes- 

 tine, the arteries of which do not ordinarily take part in the aneur- 

 ism. The sudden obliteration of a single colic or caecal artery may 

 determine light and transient colics. 



When these fragments become detached from the aneurismal 

 thrombus they are carried generally into the inferior arterial 

 branches, and especially into the right colic. The obliteration of 

 a single caecal artery is not fatal, because of the anastomosis which 

 exists between the two caecal arteries, and also because the caecum 

 is supplied by a small arterial branch coming from the inferior 

 colic artery. 



