Pancreatic exocrine function

Question 1

What are the two functions of the pancreas?

Answer 1

• Endocrine secretion
• Exocrine secretion
  (aqueous bicarbonate secretion + enzyme secretion)

Question 2

What is the pancreatic duct?

Answer 2

Runs along the inside of the pancreas and is very thin 1-4mm thick as it goes from tail to body

Question 3

How much bicarbonate do we secrete a day?

Answer 3

1 L/day

Question 4

Where is HCO3- produced ?

Answer 4

Epithelial cells in the pancreatic duct produces HCO3- and H2O

Question 5

Why is bicarbonate secreted?

Answer 5

• This secretion protects duodenal mucosa by neutralising stomach acid
• Buffers duodenal contents to optimise pH for enzyme digestion

Question 6

What initiates protein digestion?

Answer 6

Pepsin in the stomach

Question 7

Where does the majority of protein digestion occur?

Answer 7

In the small intestine

Question 8

What are some pancreatic proteases and how are they stored?

Answer 8

• Trypsin
• Chymotrypsinogen
  They are stored as trypsinogen and chymotrypsinogen

Question 9

How are pancreatic proteases activated?

Answer 9

• Trypsinogen activated by enterokinase
• Trypsin activates chymotrypsinogen and additional trypsinogen

Question 10

What do lipases hydrolyse and what aids this?

Answer 10

Triglycerides to monoglycerides and free fatty acids
- Bile salts helps aid this

Question 11

What is orlistat?

Answer 11

It is a pancreatic lipase inhibitor so stops some of the fat you eat from being absorbed. So it is used with weight loss

Question 12

What does amylase do?

Answer 12

• Hydrolyses starch to maltose (glucose- glucose disaccharide) and maltotriose (trisaccharide) and limit dextrins (low molecule carbohydrate made from starch)

Question 13

Where is amylase found?

Answer 13

• Salivary amylase has a small role
• But most is found and secreted by pancreas

Question 14

What is the cephalic stage of enzyme secretion?

Answer 14

This is the low level stimulus of anticipating a meal. Sight, smell etc…
Occurs through vagal innervation and release of gastrin

Question 15

What is the intestinal stage of enzyme secretion?

Answer 15

Secretin, Cholecystokinin, Gastrin are all secreted

Question 16

What does Cholecystokinin (CCK) do?

Answer 16

It is a pancreatic enzyme which delays gastric emptying. It does this by inhibiting the gastric acid secretion when the gallbladder contracts

Question 17

How does pancreatic secretion reduce?

Answer 17

As proteins and fats are digested and absorbed, pH rises and stimuli for CCK and secretin disappear and so pancreatic secretion falls as there is no stimulus

Question 18

What 2 hormones are vital for carbohydrate and lipid metabolism?

Answer 18

Inuline an glucagon

Question 19

What are some consequences of pancreatic exocrine insufficiency?

Answer 19

Malnutrition
Osteoporosis
Increased cardiovascular morbiditiy
Symptom burden

Question 20

How do we assess for poor pancreatic function?

Answer 20

History, risk factors
Imaging
Faecal elastase
Markers of malnutrition

Question 21

How do you treat PEI (pancreatic exocrine insufficiency)

Answer 21

Pancreatic enzyme replacement therapy
STOP smoking
Bone health assessment
Treat the underlying cause