2.8- blood glucose levels and obesity

Question 1

what is the usual concentration of glucose in blood plasma and what can alter this?

Answer 1

5 millimoles per litre

depending on demand from varying tissues

Question 2

what can blood glucose levels raise to for a person with diabetes?

Answer 2

30mmol/l

10/30

Question 3

what happens during chronic elevation and what does it cause?

Answer 3

endothelial cells lining blood vessels absorb far more glucose than normal

causes damage to blood vessels

Question 4

what may develop due to chronic elevation and what 3 conditions could this lead to?

Answer 4

atherosclerosis

peripheral vascular disease, CVD or stroke

Question 5

3 steps in microvascular disease

Answer 5

endothelial cells lining a small blood vessel take in more glucose than normal

endothelial cells may lose their strength and burst and bleed into surrounding tissues

leakage reduces blood flow through the body and it doesn’t receive an adequate oxygen supply

Question 6

3 areas microvascular disease causes damage to and how

Answer 6

retina- affecting vision

kidneys- causing renal failure

nerves in extremities- causing peripheral nerve dysfunction

Question 7

what are the bodys requirements and how does it guarantee they are met?

Answer 7

regular supply of glucose to be present in the bloodstream

body employs a system of negative feedback control known as homeostasis

Question 8

5 steps in the body’s response to an increase in blood glucose

Answer 8

receptor cells in the pancreas detect a rise in blood glucose concentration

receptor cells trigger increased secretion of insulin

insulin travels in bloodstream from pancreas to liver where insulin receptors pick it up

excess glucose absorbed by liver cells

enzyme activated to catalyse reaction of glucose to glycogen

Question 9

5 steps in the body’s response to a decrease in blood glucose

Answer 9

different receptor cells in the pancreas detect a drop in blood glucose concentration

receptor cells trigger increased secretion of glucagon which is transported to the liver

different enzyme activated to catalyse reaction of glycogen to glucose

glucose released from liver cells, returning the concentration to normal

around 100g of glucose stored as glycogen in the liver

Question 10

when does the body need additional supplies of glucose and why?

Answer 10

during exercise or the fight/flight response

provide energy quickly

Question 11

what is released and from where when the body needs energy quickly?

Answer 11

adrenal glands secrete increased quantity of adrenaline into bloodstream

Question 12

3 steps in adrenalines effect on the body

Answer 12

overrides normal homeostatic control of blood glucose level by inhibiting the secretion of insulin and stimulating glucagon secretion

this promotes breakdown of glycogen to glucose

adrenaline reduced to a minimum and blood glucose returns to normal when crisis over

Question 13

what are people with diabetes unable to do?

Answer 13

control their own blood glucose level

Question 14

3 characteristics of diabetes type 1

Answer 14

usually occurs in childhood

unable to produce insulin

treatment is regular doses of insulin

Question 15

3 characteristics of diabetes type 2

Answer 15

usually develops in later life

likelihood is increased by being overweight

insulin is produced but cells are less sensitive

Question 16

what causes the insulin resistance in type 2 diabetes and what does it lead to?

Answer 16

the decrease in the number of insulin receptors in the liver

leads to a failure in the conversion of glucose to glycogen

Question 17

what happens in both types of diabetes if left untreated?

Answer 17

results in a rapid increase in blood glucose level following a meal

Question 18

what happens to some of the excess glucose in untreated diabetics?

Answer 18

kidneys remove it which results in glucose appearing in the urine

Question 19

what can be used as an indicator of diabetes?

Answer 19

testing urine for glucose

Question 20

what is glucose tolerance and what does it depend on?

Answer 20

the capacity of the body to deal with ingested glucose

depends on the body being able to produce adequate quantities of insulin

Question 21

2 steps in the glucose tolerance test

Answer 21

blood glucose concentrations of the individual are initially measured after fasting

individual then drinks a glucose solution and changes in their blood glucose concentration are measured for at least 2 hours

Question 22

3 differences between a diabetic and non-diabetics blood glucose concentration during the glucose tolerance test

Answer 22

diabetic blood glucose concentration usually starts at a higher levels than a non-diabetic

diabetic blood glucose concentration increases to a much higher level

diabetic blood glucose concentration takes longer to return to its starting concentration

Question 23

what is obesity characterised by?

Answer 23

the accumulation of excess body fat in relation to lean tissue such as muscle

Question 24

2 conditions an individual becomes at risk for when obese

Answer 24

cardiovascular disease

type 2 diabetes

Question 25

how is body mass index calculated?

Answer 25

body mass (kg) ÷ height² (m²)

Question 26

what must a BMI be over to indicate obesity?

Answer 26

30+

Question 27

what is the downside of BMIs?

Answer 27

can wrongly classify muscular individuals as obese

Question 28

what do different BMI values indicate?

Answer 28

20-25 —> ideal for height

26-30 —> overweight

31-40 —> obese

40+ —> very obese

Question 29

5 factors thought to contribute to obesity

Answer 29

genetic

psychological

environmental

metabolic

dietary

Question 30

2 of the most common causes of obesity

Answer 30

excessive consumption of food rich in fats and free sugars

lack of physical activity

Question 31

why should the energy intake in a diet limit fats and free sugars?

Answer 31

fats have a high calorific value per gram

free sugars require no metabolic energy to be expended in their digestion

Question 32

what is the main treatment for obesity?

Answer 32

reduction in energy intake and an increase in energy expenditure

Question 33

2 reasons why exercise is beneficial as a treatment for obesity

Answer 33

increases energy expenditure

preserves lean tissue

Question 34

what does exercise help to reduce and what’s 4 ways it does this?

Answer 34

helps to reduce risk factors for CVD

keeps weight under control
minimises stress
reduces hypertension
improves blood lipid profiles