Fuel metabolism and diabetes mellitus

Question 1

What are the 2 key roles of whole body metabolism?

Answer 1

1. Storage of nutrients/breakdown of stores when required

2. Maintenance of blood glucose - brain energy source

Question 2

What are the 2 states of metabolism?

Answer 2

Fed - absorptive state - anabolic

Fasted - post absorptive state - catabolic

Question 3

What are the percentages of total energy storage molecules and where are they stored? (3)

Answer 3

Carbs - 1% - liver, skeletal muscle
Lipids - 77% - adipose
Proteins - 22% - skeletal muscle

Question 4

What is the energy balance equation?

Answer 4

Energy output = work performed + heat produced

Question 5

What is a positive energy balance?

Answer 5

Energy input > energy output

Question 6

What is a negative energy balance?

Answer 6

Energy input < energy output

Question 7

What is the energy balance during the fed absorptive state? And what is the hormonal control?

Answer 7

Positive

Insulin - anabolic

Question 8

What is the energy balance during the fasted post absorptive state? And what is the hormonal control?

Answer 8

Negative energy output

Glucagon - catabolic

Question 9

How is insulin release regulated? (3)

Answer 9

1. Glucose is absorbed into the islet of Langerhans
2. It binds to the B cells via muscarinic receptors
3. These stimulate secretions of insulin

Question 10

What happens when there is an increase in glucose?

Answer 10

Liver, muscle and adipose tissue all increase glucose uptake

Question 11

What is the result of insulin action?

Answer 11

Reduce blood glucose

Question 12

What is the effect of insulin on glucose uptake?

Answer 12

Insulin allows GLUT-4 to intake glucose into cells

Question 13

What stimulates and inhibits glucagon release? (2)

Answer 13

Stimulated by low blood glucose

Inhibited by high blood glucose

Question 14

What are the main actions of glucagon? (4)

Answer 14

Raise blood glucose
Stimulate hepatic glycogenolysis
Stimulate hepatic gluconeogenesis
Stimulate lipolysis

Question 15

What are the steps at high blood glucose? (3)

Answer 15

1. B cells activated, a cells deactivated
2. increase insulin, decreased glucagon
3. Decrease in blood glucose

Question 16

What are the bodily steps at low blood glucose? (3)

Answer 16

1. A cells activated, B cells deactivated
2. Increase in glucagon, decreased insulin
3. Increase in blood glucose levels

Question 17

What is the normal range of glucose in the blood?

Answer 17

4 - 8 mol/L

Question 18

What is hypoglycaemia? (3)

Answer 18

< 4mmol/L
Glucose deficiency in the brain
Tremors, palpitations, sweating

Question 19

What is hyperglycaemia? (3)

Answer 19

7-11mmol/L
High temp
Neuropathy

Question 20

What is the most common endocrine disorder?

Answer 20

Inappropriate glucose homeostasis

Diabetes mellitus

Question 21

What is type 1 and type 2 diabetes?

Answer 21

Type 1 - insulin deficiency

Type 2 - impaired B-cell function

Question 22

What are the long term effects of high glucose levels? (3)

Answer 22

• Glycosuria
• Visual disturbance
• urinogenital infections

Question 23

What are the consequences of impaired glucose utilisation? (3)

Answer 23

• Lethargy
• Weight loss
• Ketoacidosis

Question 24

How is type 1 diabetes caused (4) and how do you treat it?

Answer 24

• Autoimmune
• Destruction of B cells
• Genes and environmental triggers
• rapid onset
• treated with insulin, exercise and healthy diet

Question 25

How is type 2 diabetes caused (3) and how do you treat it?

Answer 25

• Relative insulin deficiency or insulin resistance
• Diet and lifestyle tend to cause or activate
• gradual onset
• diet and drugs

Question 26

What is T2DM? (2)

Answer 26

• improve insulin action

- promote insulin release

Question 27

What is T1DM and type 2?

Answer 27

Insulin