THE ABDOMEN 



791 



Otherwise the stnic- 

 Brunner's glands lie 



Brunner's Glands 



more branched, and in having longer ducts 

 ture of the two kinds of glands is similar 

 embedded in the submucous coat, and 

 their long ducts pass through the whole 

 thickness of the mucous coat, upon the 

 surface of which they open between the 

 crypts of Lieberkiilin. Some of them, 

 however, open into these crypts. The 

 glands can easily be displayed by re- 

 moving the peritoneal and muscular 

 coats of the duodenum and a little of 

 the submucous areolar tissue, when they 

 appear as small, round, grey-coloured 

 masses like millet seeds, varying in dia- 

 meter from ^V to ^jj inch. 



The crypts or follicles of Lieberkuhn 

 are foimd in large numbers over the 

 whole of the mucous membrane of 

 the small intestine, as well as that of 

 the large bowel. They belong to the 

 class of simple tubular glands, and are 

 to be regarded as small diverticula o 

 the mucous membrane. Each crypt 

 takes the form of a simple tube, which 

 is closed and slightly enlarged at its fig. 339.— Section of the 

 deep extremity, and opens by its other Duodenum, showing 

 end on the surface between the villi. Brunner's Glands 

 The crypts are present on the valvule (highly magnified). 

 conniventes as well as in the intervening 



parts. They are placed vertically and close together, and are 

 confined entirely to the mucous coat, in which they extend from 

 the free surface to the muscularis mucosae. In length they vary 

 from ^^5- to yi^ inch. Each crypt is composed of a basement 

 membrane lined with colimrmar epithelium, many of the cells 

 being mucus-secreting goblet cells, and the Imnen is of large 

 size. 



The solitary glands are present over the whole extent of the 

 mucous membrane of the small intestine. They assume the form 

 of small white round or oval nodules, which project by their 

 deep ends into the submucous coat, whilst their superficial ends 

 give rise to slight elevations of the free surface, where they have 

 the openings of the cr^'pts of Lieberkiihn placed around them. 

 They are found upon, as well as between, the valvulae conniventes. 

 In structure each solitary gland is composed of adenoid tissue 

 containing large numbers of l\Tnph corpuscles, and permeated by 

 capillary networks. Each gland is surroimded at its deep part 

 by a copious plexus of lymphatic vessels, or by l^niphatic sinuses. 

 The solitary glands are simply lymphoid nodules. 



The agminated glands or Peyer's patches are pecuhar to the 



