Heart Disease

Heart Disease

Atherosclerosis
1. lumen of artery is narrowed due to buildup of chlolesterol & fatty acid deposits below the endothelium of the artery.
  1. reduces blood flow to heart muscle cells beyond point of atheroma formation
    1. Partial blockage leads to heart muscle cells being deprived of sufficient oxygen during exercise.
      1. The cells then begin to respire anaerobically, producing lactic acid which causes painful angina.
  2. If the blood vessel is blocked completely the cells get no oxygen and begin to die, causing myocardial infaction (heart attack)
2. muscle fibres and calcium salts accumulate forming hard uneven patches called plaque.
  1. Usually occurs after damage to the artery eg. Hypertension, Bacterial Toxins etc.
Thrombosis
1. The plaque may rupture and trigger blood clotting in the damaged area, which builds up rapidly, further blocking the artery.
  1. known as a thrombus.
  2. can break up and travel elsewhere in the bloodstream, potentially leading to other problems such as a stroke.
Aneurysm
1. When the artery becomes blocked, blood flow throught the area is restricted. Pressure then builds on in front and pushes on the artery wall.
  1. this pressure causes the artery wall to weaken and start to bulge outward. This is known as an aneurysm.
    1. Vessel may rupture causing internal bleeding.
Risk Factors
1. Gender
  1. men at higher risk than women up to menopause due to effect of oestrogen
2. genetic factors
3. Smoking
  1. nicotine is a vaso-constrictor which increases blood pressure therefore causing damage to endothelium
  2. smoking increases cholestrol levels.
  3. Chemicals in cigarettes lead to increased chance of thrombosis.
4. High Blood Pressure
  1. Damages endothelium
5. High Conc. of LDL in blood.
  1. linked to excess saturated fat in diet.
  2. made in liver from fats, cholestrol and protein

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	Erstellt von Peter Nelson vor mehr als 11 Jahre