Epithelia Of The Gut Flashcards
Stratified squamous epithelia positives for GI
Resists abrasion ( mechanical and chemical )
- anus - hard substance as water removed
- oesophagus - hard as not broken down chemically
Non keratinised so it can secrete mucus to provide extra protection
Stomach simple columnar adaptations
Secrete mucus and HCO3 to form barrier to stomach acid
Which layer are the gastric glands present in
Lamina propria
Adaptations to increase SA in the gut
Permanent folds - plicae circulares
Villi
Microvilli
Where is the enterocyte present
Small intestine and colon - one cell thick
Why is the enterocyte layer one cell thick
Transportation of nutrients across the layer
Goblet cells produce mucus to protect the epithelial from:
Friction
Chemical damage
Bacterial inflammation
Chemical damage
Bacterial environment
Location of enteroendocrine cells
Located deeper in crypts and gastric glands
Function of enteroendocrine cells
Secrete hormones such as gastrin, cholecystokinin, secretin which control the function of the gut
Location of Paneth cells
Base if crypts
Function of paneth cells
Secrete antibacterial proteins
Protects stem cells
What is the specialised gland in the duodenum called
Brunner’s gland
Function of Brunner’s glands
They produce and alkaline mucoid material which is secreted into the crypts to help neutralise the acidic chyme coming from the stomach.
Why does the goblet cells produce mucus in the colon
To from a layer between the micro biome and epithelia
Processes involved in the water movement in the colon
Due to a strong concentration gradient that water must move against there are prominent lateral intercellular spaces.
There are lots of sodium potassium ATPase’s in the lateral membrane. This causes a low sodium intracellular sodium concentration. This allows sodium to re enter the cell and allow water in to the cell
