08/09 Lecture 22 - Small Intestine

Duodenum

This is a ~25 cm region of the small intestine that recieves chyme, enzymes, bicarbonate, and bile into the small intestine. Sits retroperitoneal

Jejunum

This is a ~2.5 m region of the small intestine

Ileum

This is a ~3.5 m region of the small intestine

Mesentary

This is a structure that prevents tangling of the small intestines

Plicae circulares

These are permanent folds of the small intestine, made up of a core of submucosa with overlying mucosa 

Villi

These are extensions of the mucosa that increase the surface area of the small intestine

Muscularis mucosae

This is the muscular layer of the villi that allows for villi movement

Glycocalyx

These are branched filaments of glycoproteins that tether enzymes to the small intestine

Luminal digestion

This is digestion involved in processing mostly-undigested chyme, enzymes float in the lumen

Contact digestion 

This is digestion involved in processing mostly-digested chyme, enzymes attached by the glycocalyx 

Paneth cells

These are cells in the intestinal crypt that contains granules and antibacterial enzymes

Ileocecal valve

This is a valve that regulates the passage of material from the small intestine into the large intestine