Failure of exocrine pancreas - malabsorption

Question 1

Function of the endocrine pancreas

Answer 1

Islets of Langerhans

Question 2

Exocrine pancreas function

Answer 2

Storage and synthesis of digestion enzymes

Question 3

Function of acing cells

Answer 3

Enzyme synthesis on RER

Question 4

How are enzymes released from duodenum?

Answer 4

Duodenum -> ampulla of Vater -> sphincter of Oddi -> pancreatic duct -> inactive zymogen granules -> Golgi -> RER -> acinar cells

Question 5

How is trypsinogen activated?

Answer 5

Inactive in pancreas

Activated by enterokinase to trypsin in duodenum

Question 6

How is procarboxypeptidase activated?

Answer 6

Inactive in pancreas

Activated by trypsin to form carboxypeptidase in duodenum

Question 7

How is chymotrypsin formed?

Answer 7

Trypsinogen forms trypsin

trypsin activates chymotrypsinogen to form chymotrypsin

Question 8

function of pancreatic amylase

Answer 8

Converting starch into saccharides and alpha dextrin

breaks down starches

Question 9

Bicarbonate secretion to form bile

Answer 9

H2O and CO2 combine via carbonic anhydrase -> H2CO3 -> H+ and HCO3-
Na+ enters cells and removed by H+ ATPase
HCO3- transported into intercalated duct in exchange for chlorine
Cl- moves to lumen of intercalated duct
Bicarbonate, Na+ and H2O end up in main pancreatic duct

Question 10

Secretion of NaHCO3 into duodenum

Answer 10

Acid in duodenum
Secretin from S cells
Acts on pancreatic duct cells
HCO3 produced

Question 11

Secretion of digestive enzymes into duodenum lumen

Answer 11

Fat and protein
I cells release CCK
Acts on acinar cells
Secretion of enzymes

Question 12

Treatment for insufficiency

Answer 12

• Pancreatic enzyme replacement - pancreatin (creon) which contains lipase, amylase and protease
• Dietary changes - food should be limited to meals and minimal snacks, undigestible food should be avoided, alcohol should be avoided completely
• Vitamin supplements

Question 13

Causes of pancreatic insufficiency

Answer 13

CF
Pancreatitis
Pancreatic cancer

Question 14

Cystif fibrosis

Answer 14

Defective CFTR gene doesn’t allow bicarbonate to move from ductal cells into lumen
This blocks pancreatic ducts and there is no zymogen activation
This damages acinar and ductal cells

Question 15

Difference between acute and chronic pancreatitis

Answer 15

Acute is when the gland can return to normal if the cause is removed and chronic is irreversible

Question 16

Sx of chronic pancreatitis

Answer 16

repeated bouts of pancreatitis
Loss of parenchyma and replacement by fibrosis
Irreversible impairment of exocrine function
Sparing of IoL until late stages
Commonly caused by alcohol abuse

Question 17

Pancreatic cancer

Answer 17

blockages of ducts means enzymes secreted into pancreas and not duodenum -> pt develops pancreatitis and pain
Sx include jaundice, weight loss, malaise