Lecture 1 Flashcards
1
Q
Absorption in the small intestine
A
- Gross folds (kerckring folds) - increase sa
- Villi - increase sa more
- Microvilli - on each cell, increase sa more
Total sa = 250 m2
2
Q
Small intestinal surface area
A
- Kerckring folds: mobility (peristalsis)
- Villi (& crypts ): lined by epithelial cells (enterocytes)
- Microvilli: apical projections on an enterocyte a lacteals site of lipid absorption and lymphatic vessels
3
Q
Intestinal epithelial cell barrier ( lec )
A
Single cell barrier that protects the rest of the body from anything in the external environment (the lumen)
4
Q
Small intestine mucosa parts
A
- villi: projections into the lumen covered with mature, absorptive epithelial cells (enterocytes) along with mucus-secreting goblet cells
- crypts: location where steal cells are found and cells divide to form daughter-cells that mature into epithelial cells that line the villi
5
Q
4 layers of small intestine (inner to outer)
A
- mucosa: epithelial cells which function in nutrient absorption & protection & lamina propria (mucosal immune cells)
- Submucosa: made up of connective tissue, contains lymphatic vessels & blood vessels
- Muscularis external: smooth muscle layer
- inner: circular music
- outer: longitudinal muscle - Serosa: outer connective tissue layer (protection)
6
Q
Colon
A
- Only crypts , no villi
-Epithelial cells also called colonocytes
Colonic epithelial barrier:
- different immune cells
- mucosa: single cell barrier (epithelial + goblet cells) & Latina propria (rich in immune cells)
7
Q
Microbiota
A
- Collection of all the bacteria that reside in an established environment
- bacteria outnumber human cells 10:1 (symbiotic relationship)
- influences many physiological functions - can make us healthier or contribute to chronic disease
- microbiome: all the genetic material found within the microbiota
- colon = gut microbiota, largest anatomical site for the microbiota
