A schematic presentation of other features should be sufficient. The large intestine constitutes the terminal part of the digestive system. The primary function of the large intestine is the reabsorption of water and inorganic salts. The only secretion of any importance is mucus, which acts as a lubricant during the transport of the intestinal contents. The surface of the mucosa is relatively smooth as there are no plicae circulares or intestinal villi .
Goblet cells account for more of the epithelial cells than in the small intestine.
There is only little lamina propria squeezed between the glands. The muscularis mucosae again forms two layers. Considerable amounts of fat may be found in the submucosa . The appearance of the muscularis externa is different from that of the small intestine . The inner circular layer of muscle forms the usual sheath around the large intestine, but the outer longitudinal muscle layer forms three flattened strands, the taenia coli .