Wk 9: Diabetes

Question 1

How does the pancreas act like a digestive gland?

Answer 1

• Exocrine tissue

- Secretes alkaline pancreatic juice rich in digestive enzymes into duodenum through pancreatic duct

Question 2

Islets

Answer 2

• A: Secrete glucagon + Raise blood glucose
• B: Secrete insulin + lowers blood glucose
• D: Prod gastrin + somatostatin: inhibit glucagon + insulin

Question 3

Outline the mechanism during hypoglycemia

Answer 3

• Alpha cells: glucagon
• Acts on hepatocytes: converts glycogen into glucose (glycogenolysis) + form glucose from lactic acid + aa (gluconeogenesis)
• Hepatocytes release glucose = inc blood sugar
• Hyperglycemia inhibits glucagon secretion

Question 4

Outline the mechanism of hyperglycaemia

Answer 4

• Beta cells: insulin
• Accelerates facilitated diffusion of glucose into cell
• Inc conversion glucose to glycogen (glycogenesis)
• Inc uptake of aa + protein, + fatty acid synthesis
• Blood glucose levels dec
• Hypoglycemia = no insulin release

Question 5

GLUT

Answer 5

• GLUT 4: Insulin dependant transporter. skeletal muscle + adipose tissue
• GLUT 2: Transports glucose to beta + liver cells

Question 6

What are the risks of gestational diabetes?

Answer 6

• neonatal hypoglycaemia
• Electrolyte disorders
• Respiratory distress syndrome

Question 7

Outline the mechanism of islet beta cell destruction

Answer 7

• Tcells react against b cell antigen resulting in cell damage
• Thelper activate macrophages directed at beta cells
• Cytotoxic T cells directly kill beta cells
• Locally produced cytokines damage beta cells

Question 8

What are the factors involved in the development of Type 1A diabetes?

Answer 8

• Genetic predisposition
• Environment
• Immunologically mediated beta cell destruction

Question 9

What are the factors involved in the development of Type 1B diabetes?

Answer 9

• Beta cell destruction w/ no evidence of autoimmunity
• Strongly inherited
• Episodic ketoacidosis

Question 10

What are the features of diabetic ketoacidosis?

Answer 10

• Hyperglycaemia
• Hyperketonemia
• Metabolic acidosis

Question 11

What are the signs and symptoms of diabetic ketoacidosis?

Answer 11

• Polyuria
• Weight loss
• Smell of acetone
• Ketonaemia >3mmol/L
• Blood glucose >11mmol/L
• Bicarbonate <15mmol/L or venous pH <7.3

Question 12

What is the management for diabetic ketoacidosis?

Answer 12

• Fluid replacement (0.9% sodium chloride)
• Infusion of insulin
• Potassium for hypokalemia, if <3mmol/L)

Question 13

Hyperosmolar non-ketotic hyperglycaemia

Answer 13

• Occurs in elder people
• Associated type 2
• No ketone production or severe acidosis

Question 14

What does hyperosmolar non-ketotic hyperglycaemia lead to?

Answer 14

Due to severe osmotic diuresis:

• Dehydration
• Inc blood viscosity
• Thromboembolism

Question 15

What are the diagnostic features of HNKH?

Answer 15

• Mild acidosis w/o ketone prod
• Confusion to coma
• Seizures
• Na+ + K normal
• Creatinine high

Question 16

What are the treatment for HNKH?

Answer 16

• Fluid replacement: stabilize BP, improve circulation + urine output (sodium chloride, potassium added)
• Insulin given (fluid replacement lowers plasma glucose levels)
• Prophylaxis for thromboembolism