Lifestyle and Disease

Unit 1 : Lifestyle and disease - cardiovascular disease, risk factors of cardiovascular disease, prevention and treatment of cardiovascualr disease, interpreting data on risk factors, diet and energy.

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Cardiovascular 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.
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Blood Clots

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.
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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.
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