Lifestyle and Disease

Atheroma (formation):

• Artery walls have several layers.
• Endothelium (inner lining) smooth, unbroken.
• Damage occurs to endothelium, there's a inflammatory response, white blood cells move in.
• White blood cells form lipids clump together forming fatty streaks.
• More white blood cells, lipids and connective tissue, froming a fibrous plaque (atheroma).
• Plaque partially blocks lumen of artery restricting blood flow, blood pressure increases.
• Arteries harden (atherosclerosis).

Atheromas (increase risk):

• Atheromas develop in artery wall.
• Atheromas can rupture endothelium damaging it, leaves rough surface.
• Triggers thrombosis (blood clot at site of rupture).
• Blood flow to tissues severly restricted, less oxygen.
• Three types of cardiovascular disease - heart attack, stroke & dep vein thrombosis.

How they form: Thrombosis used to prevent extreme blood loss when vessel is damaged. Series of reactions occur leading to blood clot (thrombus):

• Thromboplastin protein released from damaged blood vessel.
• Triggers conversion of prothrombin (soluble protein) into thrombin (enzyme).
• Throbin catalyses conversion of fibrinogen (soluble protein) to fibrin (insoluble fibres).
• Fibrin fibres tangle together, form mesh which platlets (small fragments of blood) red blood cells get trapped - forms blood clot.

Cause heart attack:

• Heart muscle supplied with blood by coronary artery.
• Blood carries oxygen, cells carry out respiration.
• Artery becomes completely blocked by blood clot, no oxygen recieved.
• Causes myocardinal infarction (heart attack).
• Damage/death to heart muscle.
• Symptoms: pain, shortness of breath, sweating.
• Large areas of heart effected, fatal heart failure/death.

Stroke:

• Rapid loss of brain function due to disruption of blood supply to brain.
• Caused (mostly) by blood clot in artery, reducing oxygen.

Deep vein thrombosis (DVT):

• Blood clot in vein, usually leg veins.
• Caused (sometimes) prolonged inactivity; eg. long flights.
• Risk increases with age.

Coronary Heart Disease (CVD):

• Coronary arteries blocked by atheromas, increases risk of blood clots, increasing risk of myocardinal infarction.