Introduction
The heart is the human body's hardest working organ. Throughout life it continuously pumps blood enriched with oxygen and vital nutrients through a network of arteries to all parts of the body's tissues.
In order to perform the difficult task of pumping blood to the rest of the body, the heart muscle itself needs a plentiful supply of oxygen-rich blood, which is provided through a network of coronary arteries. These arteries carry oxygen-rich blood to the heart's muscular walls (the myocardium).
 | Click the icon to see an image of the anterior heart arteries. |
If blood flow to the myocardium is interrupted, an injury known as an infarct occurs. This is also known as myocardial infarction or, more commonly, a heart attack.
 | Click the icon to see an animation about coronary artery disease. |
The Process of Atherosclerosis
Coronary artery disease is the end result of a complex process called atherosclerosis (commonly called "hardening of the arteries"). This causes blockage of arteries (ischemia ) and prevents oxygen-rich blood from reaching the heart. There are many steps in the process leading to atherosclerosis, some not fully understood.
 | Click the icon to see an image of atherosclerosis. |
Increasingly, however, researchers are studying the interactions between cholesterol and processes known as oxidation and the inflammatory response.
Cholesterol and Lipoproteins. The story begins with cholesterol and sphere-shaped bodies called lipoproteins that transport cholesterol.
- Cholesterol is a white, crystalline substance that is found in all animal cells and in animal-based foods. It is critical for many functions, but under certain conditions cholesterol can have harmful effects.
- The lipoproteins that transport cholesterol are referred to by their size. The most commonly known are low-density lipoproteins (LDL) and high density lipoproteins (HDL). LDL is often referred to as the "bad" cholesterol and HDL as the "good" cholesterol.
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