Intestines 06

This section of small intestine includes the entire mucosa and a portion of the submucosa; the muscularis mucosa ("MM") marks the boundary. The mucosa is thrown into a series of large folds, or villi ("V"), each of which has a core of lamina propria (connective tissue) and a surface epithelium with numerous tall columnar absorptive cells (enterocytes) and scattered goblet cells; the latter "stand out" because of their pale apical cytoplasm. The villus marked at the arrow was sectioned tangentially so that its core is not seen and only the apices of the epithelial cells are in the field of view. The villi are in continuity with invaginations down into the base of the mucosa, producing a series of intestinal crypts, or glands ("G"). The glands are lined by a simple columnar epithelium that is continuous with and similar to the epithelium covering the villi except that, at the bases of the glands, it is common to find a cluster of specialized cells - the cells of Paneth. These are shown in more detail in Intestines 06A, which is a higher magnification view of the region near the asterisk ("*").

Slide P-6, field P40,4 of finder slide B, 6.3X objective