Stages of atherosclerosis: 1. Endothelium becomes damaged (e.g. due to high blood pressure, or cigarette smoke)
Stages of atherosclerosis: 2. Damage causes inflammatory response. White blood cells move into the artery wall, and chemicals (cholesterol) from the blood accumulate. A deposit then builds up called an atheroma.
Stages of atherosclerosis: 3. Calcium salts and fibrous tissue build up at site and form a hard swelling (plaque), making the artery lose some of its elasticity (hardens) and causing it to narrow.
Stages of atherosclerosis: 4. Plaque makes it difficult for the heart to pump blood around the body and results in high blood pressure. Positive feedback results as the increased blood pressure makes it more likely that more plaques will form.