Page 608 - Atlas of Histology with Functional Correlations

transported from the ileum of the small intestine and to compact it into feces

for elimination. The epithelium of the large intestine contains absorptive
cells similar to those in the small intestine and numerous mucus-secreting
goblet cells that lubricate the lumen to facilitate passage of the feces. No
digestive enzymes are produced by the cells of the large intestine.

HISTOLOGIC DIFFERENCES BETWEEN

SMALL AND LARGE INTESTINES (COLON)

The large intestine lacks both plicae circulares and villi that characterize the
small intestine. Intestinal glands that are present in the large intestine are
similar to those of the small intestine. However, they are deeper (longer) and

lack the Paneth cells in their bases. Similar to small intestine, the epithelium
of the large intestine also contains enteroendocrine cells.

The goblet cells are more numerous in the large intestine epithelium than
in the small intestine. Moreover, the number of goblet cells increases from
the cecum toward the sigmoid colon of the large intestine. The lamina

propria of the large intestine also contains many solitary lymphatic nodules,
lymphocyte accumulations, plasma cells, and macrophages. The increased
presence of GALT is due to the increased population of bacteria in the colon.

In contrast to the small intestine, the muscularis externa of the large

intestine and the cecum exhibit a complete inner circular smooth muscle
layer, whereas the outer longitudinal muscle layer is arranged into three
longitudinal muscle strips called taeniae coli. The contraction, or tonus, in
the taeniae coli forms sacculations or compartments in the large intestine,

called haustra (see Fig. 15.10).

Figure 15.14 | Appendix (Panoramic View,

Transverse Section)

This figure illustrates a cross section of the vermiform appendix at a low
magnification. Its morphology is similar to that of the colon, except for certain
modifications.

The lining epithelium (1) of the appendix contains goblet cells, the lamina
propria (3), intestinal glands (5) (crypts of Lieberkühn), and a muscularis
mucosae (2). The intestinal glands (5) are less well developed, shorter, and

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