This figure also reveals the significant characteristics of chief cells (CC ), namely, the round nucleus in a basal location; the ergastoplasm, deeply stained with hematoxylin (particularly evident in some of the chief cells where the nucleus has not been included in the plane of the section); and the apical, slightly eosinophilic cytoplasm (normally occupied by the secretory granules).
The submucosa consists of connective tissue of moderate density. Present in the submucosa are adipocytes (A), blood vessels (BV), and a group of ganglion cells (GC ). These particular cells belong to the submucosal plexus (Meissner’s plexus [MP] ). The inset shows some of the ganglion cells (GC ) at higher magnification. These are the large cell bodies of the enteric neurons. Each cell body is surrounded by satellite cells intimately apposed to the neuron cell body. The arrowheads point to the nuclei of the satellite cells.
these cells are properly designated as argentaffn cells. The surface mucous cells (SMC) in the section mark the bottom of the gastric pits and establish the fact that the necks of the fundic glands are represented in the section. The argentaffin cells appear black in this specimen. The relatively low magnification permits the viewer to assess the frequency of distribution of these cells.
and accordingly, in H&E–stained paraffin sections the argentaffin cell appears as a clear cell. The special silver staining in this figure and in figure on left shows that many of the argentaffin cells tend to be near the basal lamina and away from the lumen of the gland.
KEY A, adipocytes BV, blood vessels CC, chief cells GC, ganglion cells ME, muscularis externa MM, muscularis mucosae MNC, mucous neck cells MP, Meissner’s plexus N, neck of fundic glands PC, parietal cells SMC, surface mucous cells SubM, submucosa arrows, argentaffin cells arrowheads, nuclei of satellite cells
The gastroduodenal junction marks the entry into the absorptive portion of the alimentary canal. Thickening of the circular layer of muscularis externa at this site forms the pyloric sphincter that regulates passage of chyme from stomach to intestine. The mucous secretion of the pyloric glands helps to neutralize the chyme as it enters the intestine.
Gastroduodenal junction, stomach-duodenum, monkey, H&E ×40.
The gastroduodenal junction between the stomach and the duodenum is shown here. Most of the mucosa in the micro-graph belongs to the stomach; it is the pyloric mucosa (PMuc). The pyloric sphincter appears as a thickened region of smooth muscle below the pyloric mucosa. On the far right is the duodenal mucosa, the first part of the intestinal mucosa (IMuc). The area marked by the rectangle is shown at higher magnification in figure below. It provides a comparison of the two mucosal regions and also shows the submucosal 614 glands (Brunner’s glands).
Gastroduodenal junction, stomach-duodenum, monkey ×120.
Examination of this region at higher magnification reveals that in addition to intestinal glands (IGl ) within the mucosa, there are glands within the duodenal submucosa. These are submucosal (Brunner’s) glands (BGl ). Some of the glandular elements (arrows) can be seen to pass from the submucosa to the mucosa, thereby interrupting the muscularis mucosae (MM ). The submucosal glands empty their secretions into the duodenal lumen by means of ducts (D). In contrast, the pyloric glands (PGl ) are relatively straight for most of their length but are coiled in the deepest part of the mucosa and are sometimes branched. They are restricted to the mucosa and empty into deep
Gastroduodenal junction, stomach-duodenum, monkey ×640.