Metabolism S12 - Control of metabolism

Question 1

What are maternal adaptations to pregnancy?

Answer 1

• Adjust maternal blood concentrations of nutrients
• Modify nutrient stores to cope with demand, mainly fat stores

Question 2

What metabolic changes occur during the first half of pregnancy?

Answer 2

• Stimulus to appetite
• Store more fat and glycogen
• Higher insulin:anti-insulin ratio

Question 3

What are beta-cell responses to pregnancy?

Answer 3

Hyperplasia, hypertrophy, increased insulin synthesis and secretion

Question 4

What metabolic changes occur during the second half of pregnancy?

Answer 4

• Lower insulin:anti-insulin ratio
• Reduce maternal utilisation of glucose switching to fatty acids and release of fatty acid stores

Question 5

Where are anti-insulins produced?

Answer 5

First the ovary and then the placenta secretes huge amounts of oestrogen and progesterone which all makes muscles resistant to insulin

Question 6

What is maternal ketogenesis?

Answer 6

Decrease in insulin:anti-insulin ratio means the increased availability of fatty acids are converted to ketone bodies in the liver which are used as fuel by the developing fetal brain

Question 7

What is gestational diabetes?

Answer 7

Maternal B-cells do not respond normally to increased insulin resulting in elevated blood glucose levels Usually occurs in the third trimester

Question 8

What are the consequences of gestational diabetes?

Answer 8

• Excess fetal growth
• Can result in type II diabetes

Question 9

What is the purpose of change during exercise?

Answer 9

• Meet the acute oxygen and metabolic fuel needs of muscles
• Dispose of carbon dioxide and other waste products of metabolism
• Minimise disturbances to other physiological systems

Question 10

What does the metabolic response to exercise depend on?

Answer 10

Type of exercise, intensity of and duration of exercise, physical condition and nutritional state of individual

Question 11

What changes occur running 100m?

Answer 11

• Cannot deliver extra oxygen to muscles in time
• ATP stores regenerated anaerobically producing lactate
• Cannot deliver extra glucose to muscles in time
• Need glycogen store, spares blood glucose

Question 12

What are the different phases of response to 1500m?

Answer 12

1) Initial sprint - muscle ATP and creatine phosphate used
2) Long middle phase - aerobic metabolism of glucose from glycogen and fatty acids
3) Finishing sprint - Anaerobic metabolism of glucose from glycogen

Question 13

What are the disadvantages of fatty acids as feels?

Answer 13

• Slow release from adipose tissue
• Limited carrying capacity in the blood bound to albumin
• Capacity limited uptake across mitochondrial membrane
• Can only occur in aerobic conditions

Question 14

What metabolic changes occur when running a marathon?

Answer 14

• 95% aerobic
• Muscle glycogen depleted in a few minutes
• Use of glucose from liver glycogen peaks at an hour then declines
• Utilisation of fatty acids rises steadily from 20-30 minutes into exercise

Question 15

What hormonal changes occur when running a marathon?

Answer 15

• Insulin levels fall slowly
• Glucagon levels rise
• Adrenaline and growth hormone rise rapidly
• Cortisol rises slowly

Question 16

List the benefits of exercise

Answer 16

• Better balance of lean tissue and fat
• Lower blood lipids
• Lower blood pressure
• Improve glucose tolerance
• Improve muscle sensitivity to insulin

Question 17

What is the cardiovascular response to training?

Answer 17

Lower resting heart rate Heart becomes more efficient at pumping blood

Question 18

What is the skeletal muscle response to training?

Answer 18

More and bigger fibres, more capillaries, more myoglobin, better fatty acid oxidation capacity, increased glycogen storage, increased glucose transport capacity