Endocrine Pancreas

Question 1

Pancreatic alpha cells make up ____ of pancreatic cells and release _______________

Answer 1

10%, glucagon

Question 2

Pancreatic beta cells make up ____ of pancreatic cells and release _______________

Answer 2

70-80%, insulin

Question 3

Pancreatic delta cells make up ____ of pancreatic cells and release _______________

Answer 3

3-5%, somatostatin

Question 4

Exocrine pancreatic cells release _______________

Answer 4

digestive enzymes

Question 5

Insulin alpha-beta chains linked by _____________

Answer 5

cysteine disulphide bridges

Question 6

How is insulin/glucagon degraded?

Answer 6

hydrolysis of disulphide bridges; proteolysis in kidney and liver

Question 7

Half-life of glucagon

Answer 7

6 mins

Question 8

Somatostatin-14

Answer 8

May inhibit insulin and stimulate glucagon secretion

Question 9

Islet amyloid polypeptide

Answer 9

• Co-secreted with insulin
• Cause amyloid deposits in pancreas

Question 10

Pancreatic polypeptide (F cells)

Answer 10

Inhibits bicarbonate and enzyme secretion

Question 11

How does hypoglycemia regulate insulin/glucagon secretion

Answer 11

Inhibits insulin secretion while stimulating glucagon secretion

Question 12

How does hyperglycemia stimulation regulate insulin/glucagon secretion

Answer 12

Increases insulin secretion while inhibiting glucagon secretion - alongside leucine, arginine, and vagal stimulus

Question 13

Incretins

Answer 13

• Gastric inhibitory peptide; glucose-dependent insulinotropic peptide (GIP); produced by K cells of the duodenal and intestinal mucosa
• Glicentin, oxyntomodulin, glucagon like peptides; structurally related to glucagon, released in intestines in response to a meal to enhance insulin secretion and suppress appetite

Question 14

Pancreatitis

Answer 14

• acute or chronic inflammation of the pancreas
• activation of digestive enzymes in the pancreas
• associated with lethargy, depression, vomiting, abdominal pain, etc.

**Laboratory diagnostic aids - serum amylase and lipase measurements, serum Trypsin-like Immunoreactivity (TLI)

Question 15

Pancreatic Insufficiency

Answer 15

• Inadequate production of pancreatic digestive enzymes
• Caused by atrophy of pancreatic acinar (exocrine) cells
• Characterized by weight loss and sometimes polyphagia and steatorrhea

**Laboratory diagnostic aids - serum Trypsin-like Immunoreactivity (TLI), fecal examination, fat absorption test, chymotrypsin activity test

Question 16

Diabetes Mellitus

Answer 16

• Failure to remove glucose from blood plasma
• Two main types, insulin-dependent (type I) and non-insulin-dependent (type II)
• Type I diabetes mainly results from an autoimmune disorder; destruction of beta cells of the pancreas - symptoms arise when 90% of beta cells are destroyed
• Type II diabetes is more common and associated with obesity; insulin resistance rather than the lack of insulin appears to be cause

Question 17

Hyperglycemia of Severe Injury

Answer 17

• Non-diabetic individuals who sustain extreme injuries (i.e., massive burns)
• Stress of injury increases epinephrine and norepinephrine release
• Catecholamines inhibit insulin secretion and increase glucagon secretion

Question 18

Insulinoma

Answer 18

• Insulin-secreting tumour of the pancreas
• High levels of insulin sufficiently suppress glucagon secretion
• Characterized by persistent hypoglycemia with periods of weakness, apathy, fainting, and potentially convulsions and coma