Duodenal microanatomy of the domestic cat. (Felis catus)

Abstract

Duodenal samples were taken from similar locations in six cats, processed, stained, and examined via light microscope. There were no prominent circular folds (plicae circulares) or stratum compactum (lamina subglandularis). The 1072 pm X 201 pm villi were covered by 46 pm high columnar epitheliocytes proximally which decreased in height (41 pm) distally and displayed a 1.1 - 1.7 pm striated border. Globular leukocytes, mononuclear cells, and twenty-eight goblet cells (exocrinocytus calciformis) per villus were seen. The intestinal gland (crypt of Lieberkuhn) epithelium was 20 pm tall and had a less distinct striated border. The 515 pm simple straight tubular intestinal gland layer displayed distal branching. Many mitotic figures, 12 goblet cells per gland, and occasional columnar to triangular cells with red cytoplasmic granules were seen. The thickness of the lamina propria mucosa (glandular portion) decreased from proximal to distal (563-465 pm). The lamina muscularis mucosa had two layers and decreased in thickness distally (71-28 pm). The proximal muscularis mucosa was penetrated by the ducts of submucosal (Brunner's, duodenal) glands. The tela submucosa decreased in thickness distally (593-192 pm) and contained submucosal glands with 11.5 - 75 pm lumina for the first 1.5 - 2.5 cm. However, submucosal glands could be found to a distance of 8 cm. The glandular epithelium ranged from 7.5 - 22.5 pm in height. Only one type of secretory cell was observed, with both mucous and serous properties. The tunica muscularis ranged from 190-1425 pm (median thickness of 557 pm) and had two layers.