GI Flashcards
3 Salivary glands
1) parotid
2) submandibular- lower jaw
3) sublingual- under tongue
What carbohydrate digestive enzyme is in saliva?
amylase
what lipid digestive enzyme is in saliva?
lipase
gastric juice is most significant in …… digestion
protein
how much gastric juice is produced per day?
2-3L
What pH is gastric juice? How does is the stomach protected from this?
1-3 = high acidity.
alkaline mucous protects the epithelium from low pH/high acidity
Parietal cells secrete ……. & ………
1) HCL= kills microorganisms, promotes bile & pancreatic juice, activates pepsinogen
2) intrinsic factor= required for b12 absorption
Chief cells secrete …. & …….
1) pepsinogen (pepsin converts to pepsinogen when met with acidic environment) converts to protease pepsin = breaks proteins into peptides
2) gastric lipase= breaks triglycerides into fatty acids
G cells secrete
gastrin= stimulates HCL
Extra effects of gastrin:
- pyloric sphincter relaxation
- reduced oesophageal contraction
- gastric motility
- stimulates chief cells to secrete pepsinogen
how often does the stomach empty?
2-4 hrs
Bile is produced by:
hepatocytes
how much bile is produced per day?
1L
where is excess bile stored?
gall bladder
bile salts aid in:
emulsification of lipids
Where does bile get its yellowy-green pigment from?
bilirubin from heam breakdown
Where does most absorption take place?
the small intestine
goblet cells produce
mucous
Secretin is stimulated by:
gastric acid
- released when the acidic content enters the duodenum
- it decreases HCL
- increases bicarbonate in pancreatic juice to neutralise the acid in small intestine. Neutralising= best environment for digestive enzymes
Gastric Inhibitory peptide …….. stomach acid secretion and induces ……. secretion.
decreases, insulin
cholesytokinin (CCK) is stimulated by ….. acids and ……. acids.
fatty acids & amino
- inhibits stomach emptying
- reduces hunger= promotes satiety
- increases digestive enzymes
- increases stomach motililty
how long does passage through the small intestine take?
5 hrs
What is the name of the lymphatic capillary that absorbs fats in the villi of the small intestine?
lacteal
can amino acids and monosaccharides travel through blood capillaires?
yes- they are small enough
carbs are digested as:
monosaccharides
proteins are absorbed across the ……… surface as ……… or di/tri………
apical, peptides
what do lipids package into before travelling through lacteals?
chylomicrons
what vitamin absorption is important to prevent blood-clotting?
Vitamin K
