
Overview: mucosa
This innermost layer of the small intestine is the mucosa. The mucosa is composed of three layers: a simple columnar epithelium with microvilli and goblet cells; a lamina propria of loose connective tissue in which intestinal glands are located; and a thin muscularis mucosae of smooth muscle. Beneath the mucosa is the submucosa followed by the muscularis externa and the serosa.
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Mucosa
This innermost layer of the small intestine is the mucosa. The mucosa is composed of three layers: a simple columnar epithelium with microvilli and goblet cells; a lamina propria of loose connective tissue in which intestinal glands are located; and a thin muscularis mucosae of smooth muscle. Beneath the mucosa is the submucosa followed by the muscularis externa and the serosa. 100x

- Simple columnar epithelium
This innermost layer of the small intestine is the mucosa. The mucosa is composed of three layers: a simple columnar epithelium with microvilli and goblet cells; a lamina propria of loose connective tissue in which intestinal glands are located; and a thin muscularis mucosae of smooth muscle. Beneath the mucosa is the submucosa followed by the muscularis externa and the serosa. 100x

- Goblet cells
This innermost layer of the small intestine is the mucosa. The mucosa is composed of three layers: a simple columnar epithelium with microvilli and goblet cells; a lamina propria of loose connective tissue in which intestinal glands are located; and a thin muscularis mucosae of smooth muscle. Beneath the mucosa is the submucosa followed by the muscularis externa and the serosa. 100x

- Lamina propria -
This innermost layer of the small intestine is the mucosa. The mucosa is composed of three layers: a simple columnar epithelium with microvilli and goblet cells; a lamina propria of loose connective tissue in which intestinal glands are located; and a thin muscularis mucosae of smooth muscle. Beneath the mucosa is the submucosa followed by the muscularis externa and the serosa. 100x

- Intestinal glands
This innermost layer of the small intestine is the mucosa. The mucosa is composed of three layers: a simple columnar epithelium with microvilli and goblet cells; a lamina propria of loose connective tissue in which intestinal glands are located; and a thin muscularis mucosae of smooth muscle. Beneath the mucosa is the submucosa followed by the muscularis externa and the serosa. 100x

- Muscularis mucosae
This innermost layer of the small intestine is the mucosa. The mucosa is composed of three layers: a simple columnar epithelium with microvilli and goblet cells; a lamina propria of loose connective tissue in which intestinal glands are located; and a thin muscularis mucosae of smooth muscle. Beneath the mucosa is the submucosa followed by the muscularis externa and the serosa. 100x

- Villi >
Villi are distinguishing features of the small intestine. They are finger-like projections from the surface of the small intestine into the lumen of the organ. Villi are composed of a central core of lamina propria covered by its overlying surface epithelium. The presence of villi are diagnostic for the small intestine.

Submucosa >
A submucosa of dense connective tissue separates the mucosa from the muscularis externa.

Muscularis externa >
As in many tubular organs, the muscularis externa is composed of an inner circular and an outer longitudinal layer of smooth muscle. Between these layers is Auerbach’s plexus, a network of autonomic ganglia and nerves that innervate both muscle layers.

- Auerbach’s plexus
As in many tubular organs, the muscularis externa is composed of an inner circular and an outer longitudinal layer of smooth muscle. Between these layers is Auerbach’s plexus, a network of autonomic ganglia and nerves that innervate both muscle layers.

Serosa
This innermost layer of the small intestine is the mucosa. The mucosa is composed of three layers: a simple columnar epithelium with microvilli and goblet cells; a lamina propria of loose connective tissue in which intestinal glands are located; and a thin muscularis mucosae of smooth muscle. Beneath the mucosa is the submucosa followed by the muscularis externa and the serosa. 100x