Endocrinology Part 3 (8.3)

Question 1

What are the exocrine components of the pancreas?

Answer 1

• digestive enzymes
• duct
• duodenum

Question 2

What are the endocrine components of the pancreas?

Answer 2

• islet cells (2% mass)
• hormones
• bloodstream

Question 3

What is the most common endocrine disorder in man?

Answer 3

Diabetes Mellitus

Question 4

What is insulin?

Answer 4

• polypeptide chain composed of two chains,A & B

- synthesised as a precursor molecule called preproininsulin

Question 5

What does insulin do?

Answer 5

• allows glucose uptake in muscle &adipose tissue
• allows glycolysis
• allows glycogen synthesis
• allows protein synthesis
• allows uptake of ions (K+ and (PO3)4)

Question 6

What does insulin stop from happening?

Answer 6

• gluconeogenesis
• glycogenolysis
• lipolysis
• ketogenesis
• proteolysis

Question 7

What is glucagon and what does it do?

Answer 7

• a hormone synthesised by alpha cells of the pancreas as pre-proglucagon, trimmed down
• opposes the actions of insulin
• coverts glycogen to glucose (liver)
• coverts amino acids to glucose (liver)

Question 8

Difference between Insulin and Glucagon:

Answer 8

• they act reciprocally
• Insulin, dominates in a “fed” state
• Glucagon, dominates in a “fasted” state
• ratio of insulin to glucagon = more critical than absolute concs. of each hormone

Question 9

What is diabetes mellitus?

Answer 9

• group of disorders characterised by abnormalities of metabolism-
• results in deficiency or resistance to actions of insulin
• characterised by elevated levels of glucose in the blood

Question 10

What are the different forms of diabetes mellitus?

Answer 10

• Type 1 diabetes

- Type 2 diabetes

Question 11

What are some treatments of Type 1 diabetes?

Answer 11

• Soluble insulin, produced using bacteria
• Isophane insulin, insulin mixed with zinc/protamine, forms suspension, has effect of prolonging length of action
• Insulin analogues - made by substituting key amino acid residues, making long/short acting derivatives

Question 12

Risk of Type 2 diabetes decreases with increase of BMI. True or False?

Answer 12

False - it increases towards a BMI of 25

Question 13

What happens in Type 2 diabetes?

Answer 13

• insulin secretory defect

- peripheral insulin resistance

Question 14

What happens in resistance to insulin action?

Answer 14

• loss of sensitivity to insulin
• absent/ reduced number of insulin receptors
• abnormal receptor, does not activate 2nd messenger properly
• glucose transporter molecules do not get onto cell surface

Question 15

How is Type 2 diabetes managed?

Answer 15

• weight control - get BMI < 25
• reduce fat content (esp. SFA) t
• reduce refined CHO
• at least 50% total energy from CHO (mostly unrefined)
• regular meals
• moderate alcohol consumption
• Drugs (including insulin)