The crypts contain the mitotically active population of intestinal epithelial stem cells. The intestinal villi are contiguous with glands located at the base of villi: the crypts of Lieberkuhn, or intestinal crypts. The density of goblet cells is generally more abundant in more distal segments of the intestine. The enterocytes are interspersed with goblet cells, columnar epithelial cells with abundant, poorly staining cytoplasm, representing mucin.

Enterocytes function mainly in digestion and absorption. Although individual microvilli are indistinguishable, the brush border is apparent as a faintly staining, uniform ~1 µm layer along the superficial surface of enterocytes. Enterocytes have apical microvilli (brush border). Villi are lined by columnar epithelial cells, enterocytes. The small intestinal mucosa is characterized by numerous, regularly distributed luminal papillary projections called villi. These include the plicae circulares (intestinal folds), villi, and microvilli. The small intestinal mucosa has several anatomic adaptations that serve to create an immense surface area with which to digest and absorb nutrients. The major functions of the small intestine are digestion, secretion, and absorption. The small intestine is divided into three distinct segments, from oral to aboral: duodenum, jejunum, and ileum. Structural and functional differences in specific regions of the small intestine impart differential functional capabilities to these segments. The small intestine of most domestic species is quite similar in function and histology.

Equine intestines 3d