Surface of lumen is modified to increase surface area for absorption.
What is the Plica Circularis?
Plica: thickened areas of submucosa (folds + circular)
Villi: macroscopic finger-like projections of the mucosa.
Microvilli: microscopic folds on apical surface of cells.
Crypts: between small intestine & villi.
- Paneth: base of crypts.
- -Lysosome secretion