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The Biological Basis of Heart Disease

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Atheroma, aneurysm, thrombosis, myocardial infarction?

Read on to learn what these words mean. Coronary heart disease is a major cause of death in the UK and much of the rest of the world. Risk factors associated with CHD are diet, blood cholesterolcigarette smoking and high blood pressure.

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Atheroma

This is the build up of fatty material in the walls of arteries. It is often the underlying cause that leads to heart disease.




As you can see, it leads to the narrowing of arteries, causing a lowering of blood supply. Atheroma is associated with an increased risk of aneurysm and thrombosis. Aneurysm is a ballooning of the artery which weakens the affected area. This requires urgent treatment, otherwise it is fatal if the balloon "pops". Thrombosis is a blood clot stuck in a vessel which results in less blood supply to a specific area, and the subsequent affected tissues may be starved of blood and die.

If the blood supply to the heart muscle is stopped, then a myocardial infarction occurs. This is the scientific name for a heart attack. The heart muscle (or part of it) dies as a result of a lack of oxygen from the blood.



These are different kinds of aneurysm (you don't need to learn the names).


Diet

Stuff like eggs and meat contain high levels of cholesterol which can lead up to atheroma. Plants on the other hand have little cholesterol (Disclaimer: I'm a vegetarian ^_^), so by far the easiest way to cut on cholesterol is to remove meat from the diet, especially fatty meats. Cholesterol levels are also genetically inherited, in which case diet is even more important in preventing CHD. There are two kinds of cholesterol, HDL and LDL. HDL has a positive impact on health by removing blood cholesterol and sending it to the liver; LDL has a negative impact by doing the exact opposite - carrying cholesterol from the liver to other cells in the body.


Smoking

The mechanism by which smoking causes CHD (specifically atherosclerosis = hardening of the arteries) is complex and not fully mapped out yet. However, it is known that certain substances contained in tabacco lead to artery constriction, which in turn raises blood pressure.
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