734 THE LYMPHATIC SYSTEM 



drain large segments of the intestine; (2) groups of definite and constant nodes 

 placed along the branches of the arteries in the root of the mesentery; these drain a 

 definite smaller segment of the intestine; (3) chains of nodes along the anasto- 

 motic loops of the arteries, close to the intestinal wall; these are of the type called 

 'intercalated nodes'; (4) solitary or compound follicles, situated within the 

 submucosa or capillary zone of the lymphatics. 



What may be taken as the typical arrangement of the lymphatic vessels in the 

 intestine may be seen in fig. 576. There are three zones in which the capillary 

 plexuses are spread out, namely, in the subserosa, the submucosa, and the 

 mucosa. There is an abundant plexus of large capillaries just beneath the serosa; 

 in the submucosa the plexus is also formed by large capillaries, while the mucosal 

 plexus is finer. The lymph-follicles He in the zone of the mucosal plexus, and it is 

 from this that the central chyle vessels of the villi arise. The collecting vessels 

 are formed by the union of vessels from the submucous and subserous plexuses. 

 They traverse the three sets of nodes just described. 



The lymphatics of the stomach (fig. 577). — The stomach differs from the rest of 

 the alimentary canal in its blood-supply in having a ventral anastomotic loop, 

 namely, that along the lesser curvature. Along this loop is the superior gastric 

 chain [Igl. gastricse superiores] of nodes, lying between the folds of the lesser 

 omentum, some of them being on the posterior surface of the stomach. This is 

 the most important group of nodes draining the stomach, and it has been shown 

 that the lymph-vessels from the pylorus run obliquely across the stomach to the 

 main mass of nodes near the cardia, an important point in the surgery of the 

 pylorus. The efferent vessels of the chain pass to the coeliac nodes. The vessels 

 of the greater curvature pass to a group of inferior gastric nodes [Igl. gastricae 

 inferiores], situated along the right gastro-epiploic artery, while those of the fundus 

 follow the short gastric and left gastro-epiploic vessels to the nodes which lie 

 along the splenic artery, both these sets of nodes also draining to the coeliac group. 

 There is a zone half-way between the lesser and greater curvatures, in which the 

 lymphatics are scanty. The lymphatics of the cardia connect with those of the 

 oesophagus, and the mucosal plexus of the pylorus is continuous with that of the 

 duodenum. 



The lymphatics of the duodenum. — The lymphatics of the duodenum depart 

 somewhat from the type, owing to its relations with the pancreas and the bile- 

 ducts. The collecting vessels end: — (1) in nodes ventral to the pancreas, which 

 follow the pancreatico-duodenal artery to the hepatic chain; (2) in nodes dorsal to 

 the pancreas, which follow the superior mesenteric artery to the superior mesen- 

 teric nodes. There are anastomoses between the lymphatics of the duodenum 

 and those of the pylorus, of the pancreas, and of the chain along the common 

 bile-duct. 



The lymphatics of the jejuno-ileum (fig. 578) have already served as the type 

 of the arrangement of the intestinal lymphatics (see above). The mass of 

 mesenteric nodes [Igl. mesentericse] to which the lymphatics of the small intestine 

 pass is the largest and one of the most important in the body, its individual nodes 

 numbering anywhere from 130 to 150. 



The lymphatics of the ileo-caecal region. — The surgical importance of the 

 lymph-nodes in connection with the appendix warrants a detailed description of 

 them in whicli the observations of Brodel will ])e followed. The drainage of the 

 caecum and appendix is along the ileo-colic artery, and is carried on by three sets 

 of collecting vessels — (1) an anterior ca^cal set, which generally pass through 

 one or more outlying nodes before reaching the ileo-ca3cal mesenteric nodes; (2) a 

 similar posterior set; and (3) an appendicular set, three to six in number, which 

 usually pass directly to the ileo-caical nodes. The appendix thus has an inde- 

 pendent drainage into one or two ileo-CiEcal nodes, about 3 cm. above the ileum. 

 The il(;o-ca)cal chain drains through the mesenteric nodes to the superior mesen- 

 teric group (figs. 570, 5S0). 



The lymphatics of the large intestine. — Along the ascending colon there are 

 but few nodes on the terminal vascular arches, but the numl)er increases along 

 the transverse colon, especially at its two angles. These nodes, together with 

 those along the descending and sigmoid colons, are termed the meso-colic nodes 

 [Igl. mesocolica)], and they drain partly to the superior mesenteric and partly to 

 the inferior mesenteric nodes, their efferents following the corresponding arteries. 



