Single-Layered Pseudostratified Columnar Epithelium-Duodenum

In single-layered Pseudostratified epithelium, the longitudinal axis of the cells is always oriented vertical to the tissue surface. The cells appear polygonal in cross-sections. A row of oval nuclei mostly occupy the basal part of the cell, while most of the cell organelles are locate d in the supranuclear cell region. The free surfaces of the epithelial (enterocytes ), cells in this figure have a clearly visible striate d border 1 which consists of microvilli. Sporadically, goblet cells 2 occur intersperse d with the epithelial cells of the tissue. The cells of the lamina propria mucosae 3 form a connective tissue layer underneath the epithelium, which also contains smooth muscle cells 4 , apart from blood and lymph vessels, nerve fibers and myofibroblasts. A thin basal membrane (stained blue in this section) separates the epithelium from the lamina propria mucosae 3 .

1 Brush border

2 Goblet cells

3 Lamina propria mucosae

4 Smooth muscle cells

5 Terminal web

Stain: azan; magnification: × 400

Vertical section through the lamina epithelial is mucosae of the duodenum to describe single-layered Pseudostratified columnar epithelium . The slender Pseudostratified epithelial cells are evenly covered with a brush border 1. The oval nuclei are locate d in the basal third of the cell. All enterocytes contain a large number of mitochondria, both in the perinuclear (basal) space and in the apical third of the cell 2 .

Microvilli, here seen as brush border, enlarge the duodenal surface and allow considerably more contact with the intestinal content. Microvilli-associated enzymes are important for the resorption of nutrients and digestion. The lamina propria mucosae 3 is visible in the lower part of the figure.

1 Brush border (microvilli)

2 Mitochondria

3 Lamina propria mucosae

4 Intestinal lumen

Electron microscopy; magnification: × 2000

References

Kuehnel, W.(2003). Color Atlas of Cytology, Histology, and Microscopic Anatomy. 4^th edition . Institute of Anatomy Universitätzu Luebeck Luebeck, Germany . Thieme Stuttgar t · New York .