Pancreas

Question 1

Describe the structure of the pancreas

Answer 1

lobular structure beneath stomach

Question 2

What are the 2 types of cells of the pancreas?

Answer 2

• acini
• islets of Langerhans (IoL)

Question 3

What are acini?

Answer 3

groups of exocrine cells secreting into pancreatic ducts

Question 4

What are the islets of Langerhans (IoL)?

Answer 4

groups of endocrine cells

Question 5

What is the exocrine function of the pancreas?

Answer 5

secretion of alkaline pancreatic juice containing digestive enzymes

Question 6

What is the endocrine function of the pancreas?

Answer 6

secretion of hormones (important for glucose homeostasis)

Question 7

List the pancreatic hormones

Answer 7

• insulin
• glucagon

Question 8

What type of molecule are the pancreatic hormones?

Answer 8

polypeptide hormone

Question 9

What is insulin secreted by?

Answer 9

synthesized & secreted by β-cells of the islets of Langerhans

Question 10

Why is insulin produced after feeding?

Answer 10

in response to:
- high blood glucose & amino acids
- gastrointestinal hormones
- parasympathetic nerve stimulation

Question 11

What inhibits insulin?

Answer 11

• sympathetic nerve stimulation via α2-adrenoceptors
• somatostatin from pancreatic δ-cells

Question 12

What is glucagon secreted by?

Answer 12

synthesized & secreted by α-cells of the islets of Langerhans

Question 13

Why is glucagon produced?

Answer 13

in response to:
- low blood glucose
- high blood amino acids
- gastrointestinal hormones
- parasympathetic & sympathetic nerve stimulation

Question 14

What is glucagon inhibited by?

Answer 14

• insulin from pancreatic β-cells
• somatostatin from pancreatic δ-cells

Question 15

What is the value of normal blood glucose?

Answer 15

3.5-6.0 mM

Question 16

What is hyperglycaemia and what causes it?

Answer 16

increase in blood glucose caused by:
- meal
- release of insulin
- changes in metabolism

Question 17

What is hypoglycaemia and what is it caused by?

Answer 17

decrease in blood glucose caused by:
- stress, fasting, exercise
- release of glucagon, catecholamines, GH, cortisol
- inhibition of insulin secretion
- changes in metabolism

Question 18

What is Diabetes Mellitus?

Answer 18

inability to regulate blood glucose within normal range
- type 1
- type 2
- gestational

Question 19

What is type 1 diabetes?

Answer 19

• insulin deficiency
• onset in juvenile life
• fatal without insulin treatment

Question 20

What is the insulin deficiency in type 1 diabetes caused by and how is it treated?

Answer 20

• autoimmune destruction of β-cells in pancreas
• treated: insulin injection, infusion pump

Question 21

What is type 2 diabetes?

Answer 21

• insulin resistance
• onset in later life
• maybe obesity or pregnancy

Question 22

What is type 2 diabetes caused by and how is it treated?

Answer 22

Defect in insulin signalling systems in target tissues (lifestyle, medical & genetic factors), treated by:
- healthy diet
- increased physical activity
- medication
- insulin (if needed)

Question 23

What are symptoms of diabetes mellitus?

Answer 23

• hyperglycaemia (high blood glucose)
• glycosuria
• polyuria (excessive urination)
• polydipsia (water loss → dehydration + thirst)
• polyphagia (excessive hunger)

Question 24

What is glycosuria?

Answer 24

• high filtered load of glucose at kidney
• can’t be reabsorbed totally in renal tubules
• excreted in urine