chap, xvii.] THE ABDOMINAL NERVES. 331 



of the small intestine. Several cases are recorded of 

 rupture of the ureter from external violence. When 

 such an accident occurs a large urinary collection 

 usually forms behind the peritoneum, which, leading 

 to suppuration, will produce a fluctuating tumour 

 beneath the parietes. 



The nerve supply of the abdominal viscera. 

 Some account has already been given of these nerves 

 and their communications (page 273). The abdominal 

 viscera are mainly supplied by the sympathetic system 

 through a series of remarkable plexuses. The most 

 important of these is the solar, from which is more 

 or less directly derived the nerve supply of the 

 stomach, liver, spleen, kidneys, suprarenal capsules, 

 pancreas, and such parts of the intestine as are in 

 connection with the superior mesenteric artery. The 

 solar plexus and its appendages receive the splanchnic 

 nerves and some branches from the vagus, while com- 

 munications from the phrenic go to the hepatic and 

 suprarenal plexuses. It may be well understood that 

 tin impression brought to bear upon nerve centres of 

 such extent and with such important relations would 

 produce considerable effects. These effects we see in 

 the profound collapse, vomiting, and other grave 

 symptoms that attend severe injuries to the viscera, 

 and especially to those that are the most directly asso- 

 ciated with these large centres. The descending 

 colon and sigmoid flexure are supplied by the 

 inferior mesenteric plexus, a cord that has but an 

 indirect connection with the solar plexus ; and 

 this fact may serve to account for the less serious 

 symptoms often seen in strangulation of the colon 

 when compared with a like lesion of the small 

 gut. The upper part of the colon, although supplied 

 by the superior mesenteric plexus, is only supplied by 

 that part of it that is most remote from the great 

 centres, and it is a conspicuous fact that the nearer 



