ISO 



NORMAL HISTOLOGY 



of villi, but contains crypts of Lieberkiihn closely arranged side by 

 side and lined with columnar epithelium rich in mucigenous cells. 

 The muscularis mucosae is similar to that of the small intestine, and 

 gives off occasional fibres that penetrate between the crypt-. 



The submucous coat resembles that of the small intestine, and, in 

 common with the mucous membrane, contains solitary lymph-fol- 

 licles, most abundantly in the caecum and vermiform appendix. 



The muscular coat has its outer or longitudinal layer most highly 

 developed in three bands, which are situated about equidistantly 

 around the circumference of the bowel and occasion a pouching of 

 the intervening wall. 



Fig. 129. 



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Section of human pancreas. (Bohra and Ravidoff.) a, larger duct ; b, beginning of duct ; c, d, 

 acini with cells belonging to the corresponding duct-radicles in their centers ; c. acinus, 

 cut just beyond the lumen ; /, interalveolar cell-group (?) ; g, fibrous connective tissue, 

 forming the interstitial tissue of the organ. 



The serous coat is similar to that of the small intestine, but is 

 occasionally extended over small pendulous projections of the 

 subserous fibrous tissue, which contain adipose tissue, appendices 

 epiploic*. 



8. The rectum resembles the colon in its structure, except that the 

 three muscular bands present in the latter are wanting. The mucous 

 membrane as it passes into the anal canal loses its tubular glands, 

 and subsequently become- covered, not with columnar, but with 

 stratified epithelium, continuous with the epidermis of the skin 

 around the anus. 



9. The pancreas (Fig. 129) has a structure similar to that of the 



