Pancreas And Bile Flashcards
Explain motility in the small and large intestine
Propulsion through segmentation
Which cells secrete mucus in both small and large intestine
Goblet cells
Does digestion take place in the large intestine?
No unless by bacteria
What gets digested in the small intestine
Carbs , fats, peptides and nucleic acids
What gets absorbed by active transport in small intestine
Peptides and vitamins
What gets absorbed via secondary AT in small intestine
Glucose
AA
Fructose
What gets absorbed by simple diffusion in small intestine
Fats
How does bile from liver get to gall bladder for storage before going to duodenum (SI)
Common hepatic duct
What opening allows bile to get from gall bladder to duodenum
Common bile duct and pancreatic duct
Where in the duodenum does bile go
Ampulla of vatar
Where does primary secretion of pancreatic juice come from and what is in it
Acinar cells from the acinus
Fluid with enzymes and HCO
Why is pancreatic juice at ph 8
Neutralise duodenal acid
How does fluid join to the common bile duct to duodenum
Acinar cells
Intralobular duct
Interlobular duct
Common duct
Common bile duct
Duodenum
What cells make pancreatic juice HCO rich
Duct cells
What are the 3 proteolytic enzymes in pancreas
Trypsin
Chymotrypsin
Elastase
Which 2 lipolytic enzymes are there in pancreas for fat digestion in small intestine
Lipase
Phospholipase
What are enzymes secreted as which are inactive
Zymogens
What do zymogens do which allows activation of other enzymes
Convert trypsinogen to trypsin via proteolytic cleavage / peptide cleavage
Which enzymes cleaves trypsinogen to trypsin via zymogens
Enterokinase
Give example of pro enzyme activated from trypsin
Chymotrypsinogen to chymotrypsin
Where is protein digestion completed via proteases/peptidases
Intestinal brush border membrane or cytosol
Is pancreatic acinar secretion isotonic
Yes
How does HCO get transported into duct cells before it can be transported out of apical side to the secretion
HCO/na symporter
What allows na to be high enough outside of duct cells to sumport HCO in
Na/k ATPase
H/na ATPase
How does HCO get released from duct cells into isotonic solution
HCO / Cl antiporter
What maintains Cl outside apical membrane to transport HCO out
Gets removed via CFTR
Why is there damage to pancreatic digestion in cf
They can’t transport Cl out so HCO/Cl antiporter doesn’t work
Fluid isn’t produced
Which substance from which types of cells increases HCO from duct cells when acid too high
S cells secrete secretin in duodenum
Which hormone from I cells in duodenum causes enzyme secretion from acinar cells when it detects high fat and protein
CCK
How does vagus act on acinar cells
Ach down vagus allows more enzyme secretion for digestion
How can CCK from I cells indirectly cause increased digestion
Acts on ach to stimulate acinar cells to secrete fluid
Does CCK from I cells increase bile release ?
Yes
S cells releasing secretin causes high HCO from duct cells for neutralisation. What else is neutralised
Stomach acid
What allows water movement in duct cells for na and H2O secretion
Paracellular movement between junctions in duct cells
What are the 2 roles of bile
Elimination of waste : bilirubin, cholesterol, drugs
Promotes lipid digestion and absorption
Where is bile secreted into canaliculi (gall bladder) from
Hepatocytes in liver down the common hepatic duct
How does bile enter the duodenum
Common bile duct
Do bile ducts secrete HCO?
Yes
Which 3 things make up bile
Biliary lipids (including bile acids/salts)
Bile pigment
What are the 3 biliary lipids
Bile acids/salts
Phospholipids
Cholesterol
What are bile acids/salts for
Keep cholesterol in solution
How is bile pigment bilirubin transported to the liver
Albumin
What are bile acids like cholic acids produced by
Cholesterol in liver
Or primary modification of cholesterol by bacteria
What are bile acids conjugated to to increase solubility in water
Glycine or tauro
What is the major importance of bile salts in lipid digestion and absorption
Emulsification of lipids via bile increases SA for lipase
How does bile salts go through enterohepatic recirculation
They get produced in liver and released down common bile duct to the duodenum where they are used and reabsorbed in ileum back via the portal vein
How can bile salts coat lipids/cholesterol to digest emulsify them for lipase
They are amphiphillic
Attach via hydrophobic
Opposite side facing water
What does the gall bladder do to bile
Concentrated it with lipids etc
If bile acid was too high, what would be secreted by S cells and why
Secretin
It stimulates HCO release by bile duct cells
What causes gall bladder contraction to control biliary secretion
CCK from I cells (increase bile when lipids and fats are high)
How can ach control digestion of lipids/fat
Act down vagal nerve to acinar cells for increased enzymes down bile
Why do gall stones happen
Failure of bile salts to keep cholesterol in solution
What are pigment stones
Bilirubin which hasn’t been conjugated and becomes insoluble
