Introduction lecture Flashcards
Absorption in small intestine
-Gross folds (kerckring folds)
-Villi
-Microvilli
Enterocyte or intestinal epithelial cell (IEC) barrier
single cell barrier that protects the rest of the body from anything in the external environment (the lumen)
Two structures the mucosa of the small intestinal mucosa is arranged into
-Villi
-Crypts
Villi
projections into the lumen covered predominantly with enterocytes along with occasional mucus-secreting goblet cells
Crypts
location where stem cells are found (at the base/bottom) and cells divide to form daughter cells that mature into the epithelial cells that line the villi.
4 layers of the small intestine (inner to outer)
- Mucosa –> Epithelial cells
& Lamina Propria
2.Submucosa - Muscalaris Externa
4.Serosa
Mucosa and Lamina Propria
Mucosa functions in nutrient absorption and protection
Lamina propria contains mucosal immune cells
Submucosa
made up of connective
tissue, contains lymphatic vessels and blood vessels
Muscularis externa and its layers
Smooth muscle layer
Inner: circular muscle
Outer: longitudinal muscle
Serosa
outer connective tissue layer, functions in protection
What is found in the colon? (crypts, villi)
Only crypts, no villi
Epothelial cells in colon are also called
Colonocytes
Microbiota
Collection of ALL the bacteria that reside in an established environment
Microbiome
ALL the genetic material found within the microbiota → bacteria genome
Bacteria to human cells ratio
10:1
(conservative estimates 2:1)
Where do we find 95% of bacteria
Gastrointestinal tract
Does colon have anerobic or aerobic bacteria and how much
99.9% anaerobic
What does anaerobic bacteria in the colon do
ferment/metabolize undigested CHO, fibre, protein to produce SCFA
