Histology Of Small Intestine Flashcards
3 Functions of the Small Intestine
digestion of food
Absorption of the products of digestion
Immunity
Three segments
Duodenum
Jejunum
Ileum
Plicae Circularis
Transverse folds in the inner surface of the small intestine in the mucosa and submucosa
Villi
Fingerlike and leaflike projections of the mucosa
Microvilli of the enterocytes provide the
major amplification of the luminal surface
intestinal glands or crypts
crypts of Lieberkühn
The small intestine house 6 major cell types
- Enterocytes
- Goblet cells
- Paneth cells
- M (microfold cells)
- Enteroendocrine cells
- Stem cells
Enetrocytes
Simple columnar epithelium lining the surface of the small intestine
Border of enterocytes
Microvilli covered by glycocalyx
Enterocyte Function
Lipid transport
Goblet cells
Flask shaped mucus secreting cells
Paneth cells are Located in the
basal portion of the intestinal crypts
Paneth cell granules release
lysozyme, phospholipase A2, and hydrophobic peptides called defensins, they bind and break down membranes of microorganisms and bacterial cell walls
Micro fold cells
-Epithelial cells that overlie Peyer’s patches and other large lymphatic nodules
-Specialized for transepithelial transport of particles and microorganisms
Lamina Propria of the Intestinal Villi
Heavily populated with elements of the immune system like lymphatic nodules, lymphocytes, macrophages, plasma cells, and eosinophils
