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. 100x

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

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

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

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

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 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.

A submucosa of dense connective tissue separates the mucosa from the 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 the myenteric plexus (Auerbach’s plexus), a network of autonomic ganglia and nerves that innervate both muscle layers.

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 the myenteric plexus (Auerbach’s plexus), a network of autonomic ganglia and nerves that innervate both muscle layers.

Most of the small intestine protrudes into the peritoneal cavity and is, therefore, covered by a serosa: a connective tissue layer and its overlying simple squamous epithelium (mesothelium).