Slides 246 View Virtual Slide and 247 View Virtual Slide from the UCSF collection have some excellent examples of enteroendocrine cells View Image. These are the cells with spherical nuclei and clear cytoplasm -the secretory granules of these cells are not always stained very well, but, if they are, you should note that the granules are oriented basally. You may be able to see the enteroendocrine cells View Image in this region. The cells which line the lower portions of the crypts are less well differentiated. Also, notice that there are many mitotic figures View Image. Examine several of these glands in slide 169 and note that goblet cells and enterocytes similar to those lining the villi, cover the upper portions of the gland. The epithelium lining the villi continues into the intestinal glands. You can observe the distribution of goblet cells in the intestinal epithelium stained with PAS ( slide 165). Examine the villi at a higher magnification and note that the lining epithelium consists of simple columnar cells (aka enterocytes) with a brush border and interspersed goblet cells, particularly well-demonstrated in slide 168. You can see the intestinal villi and intestinal glands (crypts of Lieberkühn). The appearance of the submucosa layer is a bit variable, but, in general, it's best considered as irregular connective tissue: in slide 29 the submucosa appears more "loose" whereas in slides 168 and 170 it is more dense, and, in slide 169, here the submucosa is edematous and exhibits unusually dilated blood vessels. The mucosa, which is clearly demarcated from the submucosa by the prominent muscularis mucosae layer, frequently shows heavy lymphocytic infiltration in the lamina propria. muscularis mucosae ( or lamina muscularis mucosae –"mucosae" here is not plural, but genitive, so this literally means "muscular layer of the mucosa").lamina propria ( or lamina propria mucosa –"propria" means "belonging to".Note that the mucosa consists of three sub-layers: View these sections with the low power objective and identify the mucosa, submucosa and the muscularis externa. Slide UCSF 247 40x (jejunum, human, H&E and silver stain) View Virtual Slide Slide UCSF 246 40x (jejunum, human, H&E stain) View Virtual Slide Slide 171 20x (jejunum, vascular inj) View Virtual Slide Slide 165 40x (ileum, Alcian blue PAS stain) View Virtual Slide Slide 170 40x (ileum, H&E) View Virtual Slide Slide 169 40x (jejunum, H&E) View Virtual Slide Slide 168 40x (ileum, H&E) View Virtual Slide Slide 29 40x (jejunum, monkey, H&E) View Virtual Slide After viewing slide 162, move to slide 161 and try to find the duodenal region in this tissue section. Observe that the ducts of these glands (and, occasionally, some acini) penetrate the muscularis mucosae and open into a crypt of Lieberkühn. ![]() Locate the duodenal portion in this slide and notice the presence of submucosal mucous glands ( Brunner's glands). Slide 161 40x (pylorus, duodenum, pancreas, H&E) View Virtual Slide Slide 162 40x (pyloro-duodenal junct, H&E) View Virtual Slide The histology of the wall of the small intestine differs somewhat in the duodenum, jejunum, and ileum, but the changes occur gradually from one end of the intestine to the other.
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