THE SMALL INTESTINE. 



1639 



are seen within the epitheUum of the villi. It is worthy of note that even in the adult 

 mitotic figures are frequently observed within the cells lining Lieberkiihn's glands, 

 although such evidences of cell-division are rare among the elements coxering the 



Fig. 1390. 



Duct of Brunner's glands 

 Villus 



Lymph- 

 node 



Brunner's 

 glands 



Gland of Lieberkuhn 



Circular 

 muscle 





Longitudinal, 

 muscle 



Serous coat. 



Longitudinal section of duodenum, showing Brunner's and Lieberkiihn's glands, villi, and lymph-node. X 100. 



villi. The lining of these crypts is an active source for the regeneration of the intestinal 

 epithelium. Migratory leucocytes are also present. Small groups of granular ele- 

 ments, the cells of Panel k, occur within the crypts, constantly in the ileum and uncer- 

 tainly in the other parts of the small intestine 



Their significance is undetermined. 



Fig. 1391. 



Pyloric glands 



Mucous 

 coat 





(sphinc ifcjil ' 

 ter m 



pylori) "i- 



Longi 

 tudinal 

 muscle 





Brunner -> glands 





Stomach 



Duodenum 



Longitudinal section through junction of stomach and duodenum, showing transition of pyloric into duodenal glands; 

 also thickening of circular muscle to form sphincter pylori. -, 23. 



The glands of Brunner, also often appropriately termed the diiodenal glands, 

 are limited to the first division of the small intestine. Beginning at the pylorus, 

 where they are most numerous and extensive, they gradually decrease in number and 



