The normal structure of regional feline gastric mucosae: scanning electron microscopic study.

Regions of cat's stomach can be identified by looking at the surface epithelial cells by scanning electron microscopy (SEM). The luminal surface of cells of the cardiac region were elongated, of the fundus rounded, of the corpus polygonal shaped, and of the pyloric region diamond shaped. The quantity and distribution of microvilli covering the epithelial cells varies, being abundant and evenly distributed in the cardiac region and gradually decreasing in number toward the gastro-duodenal junction, where they were confined to cell perimeters. The colliculi varied in shape and distribution from few in the fundus and corpus to numerous in the pyloric region. Large numbers of gastric pits were present in the corpus. They diminish toward both the cardia and gastro-duodenal junction. The cardiac and pyloric glands were coiled. The gastric glands (glandula gastrica propria) were straight tubules in the fundus and coiled in the corpus. All luminal surfaces of glandular epithelial cells were covered with microvilli, but the regional distribution of microvilli on the cell was variable. Parietal, mucous neck, and chief (zymogen) cells were identified by their cytoplasmic structure. Parietal cells had long apical microvilli, mucous neck cells contained large numbers of globular mucous granules, and chief cells were vacuolated. A few G cells (Endocrinocytus gastrointestinalis) were seen in the cardiac region, large numbers in the pyloric region, and not found in fundus or corpus.