

oj CHAPTER IX. 



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Intestinal Mucous Membrane. 



THE mucous rfnembrane of the alimentary canal is ^ eral struc - 

 continuous with the skin, and, in its essential consti- 

 tuents, possesses a similar structure ; thus, it consists 

 of two layers, one of which corresponds to, and resem- 

 bles closely, the superficial stratum of the true-skin 

 the mucous membrane proper ; the other, the ana- 

 logue of the cuticle, and like it composed of cells, is 

 the epithelium. Nevertheless, the varying shape and 

 disposition of its epithelial cells, and the peculiar 

 modes of distribution of its blood-vessels, as well as 

 Its glands, constitute a membrane $ui generis which 

 requires a description in detail. 



A general examination of this membrane shows at 

 once that its appearance and structure are not the same 

 throughout. There is evidently a considerable differ- 

 ence existing between the several segments of the 

 intestinal tube; and in view of this fact, and to faci- 

 litate our examination of the membrane, we shall 

 study its structure successively : 1st, in the mouth ; 2d, 

 in the pharynx and oesophagus ; 3d, in the stomach ; 

 4th, in the small, and lastly in the large, intestine. 



The mucous membrane of the lips, cheeks, palate, MUCOUS mem- 



braneof the 



and gums, resembles exactly the superficial stratum mouth - 

 of the true skin. It consists of a layer furnished with 

 papillae at least as numerous, and of the same shape, 



