Animal organisation - transport systems - AQAEvaluation of different treatment methods
Multicellular organisms require transport systems to supply their cells and remove waste products. In humans, one of the functions of the circulatory system is to transport substances.
Drugs used alongside heart conditions and transplants prolong life.
NHS data shows the life expectancy of heart transplant patients:
Life expectancy in years
Proportion of patients, in per cent
> 1
80 - 90
> 5
70 - 75
> 10
50
Life expectancy in years
> 1
Proportion of patients, in per cent
80 - 90
Life expectancy in years
> 5
Proportion of patients, in per cent
70 - 75
Life expectancy in years
> 10
Proportion of patients, in per cent
50
Evaluating the treatment methods
Treatment
Advantages
Disadvantages
Drugs - statins
Reduce the risk of heart attack. Studies have shown a decrease in 'bad cholesterol' and an increase on 'good cholesterol.' Used to reduce high cholesterol levels that have genetic causes.
May have beneficial effects on other conditions.
Not suitable for people with liver disease. Some side effects. Must be taken for life. Should not be taken if pregnant or breastfeeding.
Heart transplant
Improve quality of life.
Few donor hearts are available. Recovery time is long. There is a risk of rejection by the body's immune system.
Replacement heart valves
Restore blood flow through the heart.
Biological valves may wear out. Blood clots may stick to mechanical valves - anti-blood clotting drugs need to be taken.
Stents
Widen coronary arteries that have not responded to drug treatment. The recovery time is short following insertion of the stent.
In a minority of cases, further treatment is required.
Treatment
Drugs - statins
Advantages
Reduce the risk of heart attack. Studies have shown a decrease in 'bad cholesterol' and an increase on 'good cholesterol.' Used to reduce high cholesterol levels that have genetic causes.
May have beneficial effects on other conditions.
Disadvantages
Not suitable for people with liver disease. Some side effects. Must be taken for life. Should not be taken if pregnant or breastfeeding.
Treatment
Heart transplant
Advantages
Improve quality of life.
Disadvantages
Few donor hearts are available. Recovery time is long. There is a risk of rejection by the body's immune system.
Treatment
Replacement heart valves
Advantages
Restore blood flow through the heart.
Disadvantages
Biological valves may wear out. Blood clots may stick to mechanical valves - anti-blood clotting drugs need to be taken.
Treatment
Stents
Advantages
Widen coronary arteries that have not responded to drug treatment. The recovery time is short following insertion of the stent.
Disadvantages
In a minority of cases, further treatment is required.
