Page 610 - Atlas of Histology with Functional Correlations

The histology of the upper rectum is similar to that of the colon.

The surface epithelium (1) of the lumen (5) is lined with simple columnar

cells with brush borders and goblet cells. The intestinal glands (4), adipose
cells (12), and lymphatic nodules (10) in the lamina propria (2) are similar to
the colon. The intestinal glands are longer, closer together, and filled with goblet
cells. Beneath the lamina propria (2) is the muscularis mucosae (11).

The longitudinal folds (3) with a core of submucosa (8) in the upper rectum

and colon are temporary. Permanent longitudinal folds (rectal columns) are
found in the lower rectum and the anal canal.

Taeniae coli of the colon continue into the rectum, where the muscularis
externa (13) acquires the inner circular (13a) and outer longitudinal (13b)

smooth muscle layers. Between these two smooth muscle layers are the
parasympathetic ganglia of the myenteric (Auerbach) plexus (14).

Adventitia (9) covers a portion of the rectum, and serosa covers the
remainder. Numerous blood vessels (6, 7, 15) are in both the submucosa (8) and
the adventitia (9).

FIGURE 15.15 ■ Rectum (panoramic view, transverse section). Stain:
hematoxylin and eosin. Low magnification.

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