THE LYMPHATICS OF THE ABDOMEN. 



977 



three more or less distinct lymphatic areas (Fig. 817). Not that the areas are 

 perfectly separated from one another ; on the contrary, the subserous net-work is 

 continuous over the entire surface. But the collecting stems from each area follow 

 a definite route toward different node groups. The largest of these areas occupies 

 roughly the whole of the upper border of the stomach from the fundus to the 

 pylorus, and extends downward on either surface to about two-thirds of the distance 

 to the crreater curvature. Its collecting stems all pass to the superior cardiac nodes. 

 The second area occupies about the pyloric two-thirds of the greater curvature, and 

 its efferents pass to the inferior gastric nodes, while the third and smallest area 

 occupies the lower part of the fundus and the cardiac one-third of the greater 

 curvature, and sends its efferents to the splenic nodes. It may be remarked that 

 these areas correspond in a general way with the areas drained by the principal veins 

 arising in the stomach walls. Thus, the large upper area corresponds in general with 

 the drainage area of the gastric vein, the lower pyloric area to that of the right 

 gastro-epiploic vein, and the lower cardiac area to that of the left gastro-epiploic. 

 it may further be noted that while the subserous net-work communicates with the 

 superficial net- work of the oesophagus, it seems to be completely cut off from connec- 

 tion with the corresponding duodenal net-work, an arrangement which is in striking 

 contrast "to the continuity which 



Fig. 819. 



Mesenteric lymphatic nodes and vessels ; peritoneal covering of 

 mesentery has been removed. 



exists between the gastric and 

 duodenal mucosa net-works and 

 explains the rare extension of a 

 carcinomatous infection of the 

 pylorus to the duodenum by the 

 subserous route. 



The Small Intestine. — 

 Throughout the entire length of 

 the intestine, both small and large, 

 the lymphatic net - works are 

 arranged in two sets, one of which 

 is situated in the mucosa and the 

 other in the muscular coat. The 

 two net-works are more or less 

 independent, though communicat- 

 ing branches occur, and both open 

 into a subserous net-work from 

 which collecting stems arise. 



The stems which pass from 

 the duodenum are divisible into 

 two groups according as they arise from the anterior or posterior surface. Those 

 coming from the anterior surface pass to the chain of nodes situated along the 

 course of the inferior pancreatico-duodenal artery, and so to the coeliac nodes, 

 which surround the origin of the superior mesenteric artery, while the posterior 

 stems pass to the hepatic nodes situated along the course of the superior pancreatico- 

 duodenal vessels and so to the cceliac nodes which surround the coeliac axis. Some 

 of the stems which take their origin from the first part of the duodenum pass to 

 those nodes of the inferior gastric group which are situated upon the posterior 

 surface of the pyloric region of the stomach, and, since these nodes also receive 

 afferents from the pylorus, they afford opportunity for the transference of a superficial 

 infection from the pylorus to the duodenum, a direct route for infection in this 

 direction being wanting (see above). 



The collecting stems of the jejunum and ileum pass to the first series of 

 mesenteric nodes, situated along the line of attachment of the mesentery to the 

 .intestine, and, after traversing these, are continued onward to the second and third 

 series of nodes, whose efferents pass to the coeliac nodes surrounding the origin of 

 the superior mesenteric artery. The vessels issuing from the jejuno-ileum are usually 

 spoken of as the lacteals, on account of their contents, especially at times when 

 absorption of food constituents is proceeding rapidly in the intestine, having a milky 

 appearance, owing to the presence of numerous fat globules in the lymphocytes. 



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