AS EDEXCEL BIOLOGY UNIT 1 NOTES - CARDIOVASCULAR DISEASE (CVD)

MOST CVD STARTS WITH ATHEROMA FORMATION...

1. Artery walls are made up of layers (see heart & blood vessel notes)

2. Inner lining normally smooth & unbroken.

3. If damage occurs (EG by high blood pressure) there will be an inflammatory response - white blood cells move into area.

4. White blood cells & lipid accumulate & clump together.

5. Builds up more and more over time - it hardens to a fibrous plaque - an ATHEROMA.

6. Plaque partially blocks lumen of artery - restricts blood flow - causes pressure increase.

7. Hardening of arteries caused by atheromas = ATHEROSCLEROSIS.

ATHEROMAS - INCREASE RISK OF THROMBOSIS IN ARTERIES...

1. Atheroma can rupture through endothelium - damages wall & leaves a rough surface.

2. Triggers thrombosis (blood clotting) - blood clot forms at rupture site. (see below for blood clot formation)

3. Clot can cause complete blockage. Or become dislodged and block other vessels elsewhere.

4. Blood flow to tissues severely restricted by blood clot…