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HANDBOOK OF PHYSIOLOGY. 



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(2.) Brunner' s glands (fig. 260) are confined to the duodenum; they 

 are most abundant and thickly set at its commencement, diminish grad- 

 ually as the duodenum advances. They are situated beneath the mus- 

 cularis mucosa3, imbedded in the submucous tissue; each gland is a 

 branched and convoluted tube, lined with columnar epithelium. As 

 before said, in structure they are very similar to the pyloric glands of 

 the stomach, and their epithelium undergoes a similar change during 

 secretion; but they are more branched and 

 convoluted r.nd their ducts are longer. 

 (Watney.) The duct of each gland passes 

 through the mnscularis mucosae, and opens 

 on the surface of the mucous membrane. 



(3.) The glands of Peyer occur chiefly 

 but not exclusively in the small intestine. 

 They are found in greatest abundance in 

 the lower part of the ileum near to the 

 ileo-cascal valve. They are met with in 

 two conditions, viz., either scattered sin- 

 gly, in which case they are termed glandules 

 solitaries, or aggregated in groups varying 

 from one to three inches in length, and 

 about half-an-inch in width, chiefly of an 

 oval form, their long axis parallel with that 

 of the intestine. In this state, they are 

 named glandules agminate?, the groups be- 

 ing commonly called Peyer^s patches (fig. 

 261), and almost always placed opposite 

 the attachment of the mesentery. In 

 structure, and in function, there is no 

 essential difference between the solitary 

 glands and the individual bodies of which 

 each group or patch is made up. They 

 are really single or aggregated masses of 

 adenoid tissue forming lymph-follicles. In 



the condition in which they have been most commonly examined, each 

 gland appears as a circular opaque-white rounded body, from -fa to inch 

 (1 to 2 mm.) in diameter, according to the degree in which it is devel- 

 oped. They are principally contained in the submncous coat, but some- 

 times project through the muscularis mucosce into the mucous mem- 

 brane. In the agminate glands, each follicle reaches the free surface of 

 the intestine, and is covered with columnar epithelium. Each gland is 

 surrounded by the openings of Lieberktihn's follicles. 



The adjacent glands of a Peyer's patch are connected together by 

 areolar tissue. Sometimes the lymphoid tissue reaches the free surface, 



Fig. 260. Vertical section of du- 

 odenum, showing a, villi ; 6, crypts 

 of Lieberkiihn, and c, Brunner's 

 glands in the submucosa s, with 

 ducts, d ; muscularis mucosae, m; 

 and circular muscular coat. /. 

 (Schofield.) 



