Pancreas Flashcards Preview

Chandy- GI Physiology > Pancreas > Flashcards

Flashcards in Pancreas Deck (11)
Loading flashcards...
1

trypsin

"master enzyme" in the pancreas. It is secreted as the zymogen trypsinogen. Once it reaches the duodenum, it is converted by the brush-border enzyme enterokinase (enteropeptidase) into the active enzyme trypsin. Trypsin then activates all the other zymogens. If trypsin gets activated inside the pancreas, it will convert all the other zymogens to their active forms in the pancreas, leading to tissue damage.

Trypsin converts pro-colipase to colipase

2

cystic fibrosis

cause: mutated cAMP-activated CFTR chloride channel which provides luminal Cl for HCO3 secretion (Chloride and bicarbonate are exchanged for each other at the pancreatic ductal apical membrane)

3

pancreatitis

symptoms: Severe upper abdominal pain radiating to the back, worse after eating, nausea, vomiting, Cullen’s and Grey-Turner signs may be positive.

dx: Serum amylase and lipase will increase

cause: chronic alcoholism

4

bile salts

amphipathic

Primary bile acids, cholic acid and chenodeoxycholic acid are synthesized from cholesterol. Secondary bile acids, deoxycholic acid and lithocholic acid are produced by biotransformation of primary bile acids by intestinal bacteria.

reabsorbed actively into hepatic portal circulation via an apical Sodium-dependent Bile salt Transporter in the terminal ileum

key enzyme responsible for converting cholesterol to primary bile acids is cholesterol 7α-hydroxylase, the rate-limiting enzyme of this pathway. This enzyme is inhibited by bile salts

5

secretin

from S cells in the duodenum and jejunum stimulates pancreatic bicarbonate secretion. Secretin also simulates hepatic and biliary duct cells to secrete bicarbonate and water, which expands the volume of bile and increases its flow into the intestine. (choleretic)

In stomach: Acts on D cells to cause the secretion of somatostatin, which in turn suppresses gastrin secretion by G cells and acid secretion by parietal cells. AND decreases action potentials and phasic contractions and thereby reduces gastric motility and slows gastric emptying.

6

gallstones

symptoms: right upper quadrant pain with nausea and vomiting

7

cholestyramine

Cholestyramine, Colestipol and Coleselvalam are cationic resins that bind to anionic bile salts in the colon and reduce bile salt-induced diarrhea.

8

Pancrelipase

an enriched preparation of pancreatic enzymes including amylase, lipase and proteases. It is used to treat pancreatic insufficiency

9

Ursodeoxycholic acid

treats cholesterol gall stones

10

biliary colic

symptoms: tenderness in the right upper abdominal quadrant (right subcostal), sever pain after meals,

cause: stone gets impacted in the cystic duct and prevents outflow when the gall bladder contracts

risk factors: (“fat”, “forty”, “female”)

11

Cholecystokinin

hormone released from I cells in the intestine when fat and protein rich chyme enters the duodenum. It functions to cause gall bladder contraction, relaxation of the Sphincter of Oddi, to induce enzyme secretion by pancreatic acinar cells, and to delay gastric emptying