Coronary Heart Disease and Risk Factors 1.5-1.11, 1.15-1.16 and 1.18 Flashcards
How does cardiovascular disease start?
With atheroma formation
What is atherosclerosis?
Hardening of the arteries caused by atheromas
Describe the events leading to atherosclerosis:
- The endothelium wall of an artery is damaged
- Inflammatory response (where white blood cells move into the area)
- White blood cells and lipids clump under endothelium to form fatty streaks
- Over time a fibrous plaque is formed = ATHEROMA
- Plaque partially blocks the lumen of the artery, restricting blood flow and casing blood pressure to increase
Describe how atheromas can increase the risk of thrombosis in arteries
- Atheroma can rupture the endothelium of an artery, damaging it and leaving a rough surface
- Triggers thrombosis and blood clot forms at site
- Blood clot can block artery or dislodge and block a blood vessel elsewhere
- Blood flow to the tissues is severely restricted so less oxygen = damage
Name three forms of CVD that can be caused by blood clots
1) Heart Attack
2) Stroke
3) Deep Vein Thrombosis
Describe the blood clotting process:
- Thromboplastin (protein) is released from the damaged blood vessel
- Triggers, along with calcium ions, the conversion of prothrombin (soluble protein) to thrombin (enzyme)
- Thrombin catalyses the conversion of fibrinogen (soluble protein) to fibrin (solid insoluble fibres)
- Fibrin fibres form a mesh where platelets and red blood cells get trapped = blood clot
Name the factors that increase the risk of CVD (DISHGAG)
Diet Inactivity Smoking High blood pressure Gender Age Genetics
Explain how diet increases risk of CVD
1) High in saturated fat = more cholesterol = increased atheroma formation = increased chance of blood clots
2) High in salt = high blood pressure
Explain how high blood pressure increases risk of CVD
Increases risk of damage to endothelium in arteries = risk of atheroma = risk of blood clot = CVD
Explain how smoking increases risk of CVD (3)
1) Carbon monoxide combines with haemoglobin = reduces amount of oxygen transported in blood = tissues starved of oxygen = heart attack/stroke of heart/brain tissue doesn’t get oxygen
2) Nicotine makes platelets sticky = more chance of clots = CVD
3) Decreases amount of antioxidants (protect cells from damage) in blood so more cell damage in artery walls = more likely to be atheroma
Explain how inactivity increases risk of CVD
Increases blood pressure
Explain how genetics increases risk of CVD
Inheritance of alleles that are more likely to give a person high blood pressure or high cholesterol
Explain how age increases risk of CVD
Plaque builds up over time
Explain how gender increases risk of CVD
Men are 3x more likely to suffer CVD
Due to lack of oestrogen = higher levels of cholesterol in blood
Define risk
The chance of something unfavourable happening
Why do people overestimate risk?
- Rare
- Consequence is large
- Exposure to negative information
Why do people underestimate risk?
- Unaware of consequences
- Common
Consequences aren’t severe
What is the purpose of antihypertensives? + example
To reduce blood pressure
eg. Beta-blockers (reduce strength of heartbeat)
eg. vasodilators ( widen blood vessels)
eg. diuretics (reduces blood volume)
What are benefits/risks of antihypertensives?
Benefits = work in different ways so can be combined AND blood pressure easily monitored at home
Risks = palpitations, fainting, headaches and drowsiness
What is the purpose of statins?
To reduce blood cholesterol by reducing amount of LDL cholesterol produced in liver
What are the benefits/risks of statins?
Benefits = reduce risk
Risks = muscle/joint pain, digestive system problems anger increased risk of diabetes
What is the purpose of anticoagulants?
To reduce blood clotting
Eg. Warfarin
What are the benefits and risks of anticoagulants?
Benefits = prevent any existing clots from growing and prevent new clots altogether
Risks = causes excessive bleeding (fainting/death), allergic reactions, swelling of tissues
What is the purpose of platelet inhibitory drugs?
Type of anticoagulant that prevent platelets clumping together to form a blood clot
