Page 606 - Atlas of Histology with Functional Correlations

FIGURE 15.12 ■ Large intestine: colon wall (transverse section). Stain:
hematoxylin and eosin. ×30.

Figure 15.13 | Large Intestine: Colon Wall

(Transverse Section)

The wall of an undistended colon exhibits temporary folds (8) that consist of
both the mucosa (10–12) and submucosa (13) layers. The four layers of the
colon wall that are continuous with those of the small intestine are the mucosa
(10–12), submucosa (13), muscularis externa (14), and serosa (5).

Villi are not present in the colon. The connective tissue lamina propria (11)

contains long intestinal glands (1, 9) (crypts of Lieberkühn) that continue
through the lamina propria (11) to the muscularis mucosae (2, 12).

The lining epithelium (10) in the colon is simple columnar and
characterized by goblet cells (10) that also line the intestinal glands (1, 9). In the

illustration are intestinal glands (1, 9) that are sectioned both longitudinally and
in cross sections (9).

As in the small intestine, the lamina propria (11) contains diffuse lymphatic
tissues. A distinct lymphatic nodule (3) is visible deep in the connective tissue
of the lamina propria (11). Some of the larger lymphatic nodules may extend

through the muscularis mucosae (2, 12) into the connective tissue of the
submucosa (13).

In contrast to the small intestine, the muscularis externa (14) of the colon is
atypical. The longitudinal layer (14) is arranged into strips or bands of smooth

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