KEY BV, blood vessels CG, cardiac glands FG, fundic glands L, lumen LN, lymphatic nodule M, mamillated areas ME, muscularis externa MM, muscularis mucosae Muc, mucosa P, gastric pits PC, parietal cells SM, smooth muscle cells SubM, submucosa arrows: top left figure, three differently stained regions of fundic mucosa; Top right figure, opening of gastric pits asterisks, submucosa in ruga dashed line, boundary between cardiac and fundic glands
The epithelial lining of the alimentary canal is a regularly renewing epithelium; each portion has a characteristic turnover time and stem cell location. In the stomach, stem cells are located in the mucous neck. Cells that migrate upward to form the mucous cells of the gastric pit and surface have a turnover time of 3 to 5 days; cells that migrate downward to form the parietal cells, chief cells, and enteroendocrine cells of the glands have a turnover time of about 1 year.
Fundic glands, stomach, monkey, H&E ×320.
This figure shows an area of the fundic mucosa that includes the bottom of the gastric pits and the neck and deeper part of the fundic glands. It includes the areas marked by the arrows in top left figure of Plate 56. The surface mucous cells (SMC) of the gastric pits are readily identified because the mucous cup in the apical pole of each cell has an empty, washed-out appearance. Just below the gastric pits are the necks (N ) of the fundic glands, in which one can identify mucous neck cells (MNC ) and parietal cells (PC ). The mu612 cous neck cells produce a mucous secretion that differs from that produced by the surface mucous cells. As seen here, the mucous neck cells display a cytoplasm that is lightly stained; there are no cytoplasmic areas that stain intensely, nor is there a characteristic local absence of staining as in the mucous
Submucosa, stomach, monkey, H&E ×320.
This figure shows the bottom of the stomach mucosa, the sub-mucosa (SubM ), and part of the muscularis externa (ME ). The muscularis mucosae (MM ) is the deepest part of the mucosa. It consists of smooth muscle cells arranged in at least two layers. As seen in the photomicrograph, the smooth muscle cells immediately adjacent to the submucosa have been sectioned longitudinally and display elongate nuclear profiles. Just above this layer, the smooth muscle cells have been cut in cross section and display rounded nuclear profiles.
Gastric glands, stomach, silver stain ×160.
Enteroendocrine cells constitute a class of cells that can be displayed with special histochemical or silver-staining methods but that are not readily evident in H&E sections. The distribution of cells demonstrable with special silver-staining procedures is shown here (arrows). Because of the staining procedure,
Gastric glands, stomach, silver stain ×640.
At higher magnification, the argentaffn cells (arrows) are almost totally blackened by the silver staining, although a faint nucleus can be seen in some cells. The silver stains the secretory product lost during the preparation of routine sections, cup of the surface mucous cells. The mucous neck cells are also the stem cells that divide to give rise to the surface mucous cells and the gland cells.
Parietal cells are distinctive primarily because of the pronounced eosinophilic staining of their cytoplasm. Their nucleus is round, like that of the chief cell, but tends to be located closer to the basal lamina of the epithelium than to the lumen of the gland because of the pearlike shape of the parietal cell.