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The circulatory system in humans – WJECCoronary heart disease

The proper functioning of the circulatory system is essential for health. Blood transports substances around the body to every cell and removes toxic waste. It also defends against disease.

Part of Biology (Single Science)Cells, organ systems and ecosystems

Coronary heart disease

The coronary arteries supply blood to the heart muscle. These may become blocked by a build-up of fatty containing , resulting in coronary heart disease.

Diagram of a heart with the left and right coronary arteries labelled. A zoomed section shows plaque building up on the walls of the left coronary artery.

If a coronary artery is blocked, the blood supply to part of the heart muscle is cut off. That part of the heart cannot continue to contract, causing a heart attack.

Cross-section of two arteries, one labelled 'Normal artery', the other 'Narrowing of artery'. The diagram shows how plaque causes abnormal blood flow in affected arteries.
Figure caption,
Cross-section showing how plaque causes abnormal blood flow in affected arteries

Possible causes of coronary heart disease

These include:

  • poor diet – eating more tends to increase cholesterol levels
  • stress and smoking – increases blood pressure
  • salt – eating too much causes high blood pressure
  • lack of exercise
  • genetic factors
Overweight man’s belly being measured with tape
Image caption,
Lack of exercise and being overweight can increase the risk of coronary heart disease

There is no one perfect cure for disease. There are many different treatments which have both advantages and disadvantages.

TreatmentDescriptionAdvantagesDisadvantages
StatinsA daily medication to control blood cholesterol levelsDrugs reduce blood cholesterol levelsMay cause side effects
AngioplastySurgery to insert a small balloon into a blood vessel which is then inflated to remove a blockageImproved blood flow in coronary vessels preventing heart attackSometimes only a temporary measure
Lifestyle changesDiet and exercise, stopping smoking etcReduces risk of heart disease and reduces blood pressureA high level of willpower is required to maintain the changes
Statins
DescriptionA daily medication to control blood cholesterol levels
AdvantagesDrugs reduce blood cholesterol levels
DisadvantagesMay cause side effects
Angioplasty
DescriptionSurgery to insert a small balloon into a blood vessel which is then inflated to remove a blockage
AdvantagesImproved blood flow in coronary vessels preventing heart attack
DisadvantagesSometimes only a temporary measure
Lifestyle changes
DescriptionDiet and exercise, stopping smoking etc
AdvantagesReduces risk of heart disease and reduces blood pressure
DisadvantagesA high level of willpower is required to maintain the changes