322 ABDOMEN 



surrounds the superior mesenteric artery like a sheath. From 

 it filaments are prolonged to the intestine along the various 

 branches of the artery. As the nerves approach the bowel, 

 some of the twigs leave the vessels and effect a series of com- 

 munications with each other in the intervals between the 

 arteries. 



The superior mesenteric plexus is an offshoot from the 

 cceliac plexus^ and it distributes twigs to the jejunum and 

 ileum, and to the right half of the large intestine. 



Lymphoglandulse Mesentericae. The mesenteric lymph 

 glands are very numerous indeed, considerably over a 

 hundred in number. They lie between the layers of the 

 mesentery and, in health, they rarely attain a size greater than 

 that of a small bean, whilst they may be as small as a pin 

 head. They form three main groups. First, a series of juxta- 

 intestinal glands, situated near the gut ; next, an intermediate 

 group, associated with the larger branches of the jejunal and 

 ileal arteries ; and thirdly, a group of large glands placed close 

 to the trunk of the superior mesenteric artery. 



The lacteah, which are the lymph vessels of the intestine, 

 issue from the wall of the gut in enormous numbers. They 

 also form a series of relays. First, those which pass from the 

 intestine to the juxta-intestinal glands ; secondly, those which 

 connect the various glands together; and finally, a group of 

 efferent vessels, from the largest glands, which fuse together 

 to form a common intestinal trunk. The common intestinal 

 trunk terminates in the cisterna chyli, which will be displayed 

 in a later dissection. 



Lymph glands are also found on the walls of the large 

 intestine, along its concave border, and in association with 

 the branches of the arteries which supply it. The lymph 

 from the csecum, the vermiform process, the ascending colon, 

 and the transverse colon passes to the common intestinal 

 trunk, through lymph vessels which accompany the arteries 

 of supply to the parts named, and so to the cisterna chyli. 

 The lymph from the descending colon, the iliac colon, and 

 the pelvic colon passes along vessels and through the lymph 

 glands associated with the branches and the trunk of the 

 inferior mesenteric artery, and thence to the lumbar glands, 

 whence it is conveyed to the cisterna chyli. 



Arteria Mesenterica Inferior. The inferior mesenteric 

 artery, considerably smaller than the superior mesenteric, 



