Animal organisation - transport systems - AQAWays of treating cardiovascular disease
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 and surgery can help to control coronary heart disease.
Statins
Statins are drugs that help to lower cholesterol in the blood. They do this by lowering its production in the liverThe large organ, beside the stomach, which has many functions, including processing substances absorbed by the digestive system and a role in the storage of the body's carbohydrate..
Statins are prescribed for people with heart disease or who have a high risk of developing it. They need to be taken long-term. cholesterolA type of lipid (fatty substance). levels will rise again if a person stops taking them.
Some studies have raised concerns regarding the side effects of statin use, while others believe they can bring additional positive benefits.
Statins are not suitable for everyone - they should not be prescribed for people with liver disease, or pregnant or breast feeding women.
Some patients taking statins often experience side-effects such as headaches and memory loss. There have been reports of statins being linked with type 2 diabetesA serious disease in which the body is unable to regulate blood sugar. and liver damage.
Other people argue that statins should be used more widely. They may protect against other conditions such as Alzheimer's disease A disease in which the brain degenerates and short term memory is lost., but further research is needed.
Stents
Coronary arteries that are blocked or have become narrow can be stretched open and a stentA device, consisting of a wire mesh tube, used to keep a narrowed or blocked coronary artery open. inserted to restore and maintain blood flow.
They can be used in instances where drugs are less effective, and offer a longer term solution. Stents are made from metal alloyAn alloy is a mixture of two or more elements, at least one of which is a metal. and do not lead to an immune response in the patient.
Around 75 000 operations are carried out each year. Risk factors depend on the patient's:
age
general health
whether they have had a heart attack
The operation is safe as it does not involve surgery, but there is a risk of bleeding, heart attack or stroke.