Intestinal epithelium
The single columnar epithelium of the small intestine consists of different epithelial cells. The palisade-like epithelial cells are tightly connected with cell junctions. The intestinal epithelium is folded into finger-like projections called the villi. Each villus contains blood and lymph vessels that efficiently distribute the nutrients that were absorbed by the cells of the intestinal lining. These are key targets for pathogens, therefore the intestinal lining is an important barrier that is well guarded by the immune system.
Figure 1: Components of the intestinal epithelium: (1) villi, (2) lymphatic vessel, (3) blood vessels, (4) gland (crypt of Lieberkuhn), (5) epithelium , (6) lymphocytes, (7) lamina propria, (8) goblet cell, (9) microvilli, (10) tight junction, (11) adhesive belt, (12) desmosome, (13) gap junction, (14) nerve ending, (15) capillary.