Heart Diseases Flashcards
What is atherosclerosis ?
Atherosclerosis is the hardening of the arteries, which is caused by the build up of plaque called an atheroma.
What is plaque ?
Plaque is the build up of fatty substances, cholesterol, calcium and other materials in the inner walls of the arteries.
Describe the process for atherosclerosis ?
- The endothelium which lines the arteries is damaged, this may be due to high blood or smoking pressure and high cholesterol levels.
- this triggers an inflammatory response, causing white blood cells to move into the artery.
- Overtime plaque builds up and leads to the narrowing of the artery restricting blood flow.
- This leads to the increase in blood pressure which in turn damages the endothelial lining and the process is repeated - example of positive feedback.
Risk factors for atherosclerosis
- **Genetics ** (genetic predisposition to high blood pressure )
- Age (arteries become less elastics wit age)
- Diet ( diet can increase cholesterol and calcium salts )
- Smoking (nicotine narrows arteries)
How can we reduce the risk of CVD
- Stop smoking
- Exercising regularly
- Reducing alcohol consumption
- Healthier diet
What can atherosclerosis lead to ?
Stroke
Angina
Myocardial infraction
Aneurisms
Explain the process of Thrombosis ?
- Damage to the endothelium exposes collagen.
- Platelets then attached to these exposed collagen fibre.
- Thromboplastin is released from the platelets and this triggers the conversion of inactive prothrombin (a protein) to active thrombin (an enzyme).
- In order for this conversion to occur calcium ions and vitamin K must be present. These are known as clotting factors.
- Thrombin catalyses the conversion of soluble fibrinogen into insoluble fibrin
- Fibrin forms a mesh which traps red blood cells to form a clot.
Explain why high blood pressure can increase the risk of developing cardiovascular disease
(CVD). (3)
Diet is one factor that affects the development of CVD.
Explain how the diet of a person could affect the development of CVD. (4)
Describe the role of LDLs in the development of atherosclerosis. (3)
- LDLs transport cholesterol in the blood stream.
- Cholesterol is then diposited into the artery wall.
- This then leads to the formation of plaque in the endothelium of the atery.
Explain how atherosclerosis can result in damage to heart muscle. (3)
Describe the role of thrombin in blood clotting.(3)
Explain why a mutation in the gene coding for the protein factor V may increase the risk
of VTE.
(3)
Explain why the location of the blood clot would affect the oxygen saturation of the blood
leaving the right lung.
An ischaemic stroke occurs when a blood vessel in the brain is blocked by a blood clot.
Explain how a blood clot could form in a blood vessel.
(4)
A person with very high blood pressure has an increased risk of developing atherosclerosis.
(i) Describe how very high blood pressure could result in atherosclerosis.
(3)
Explain how atherosclerosis in one part of an artery could increase the likelihood of it
developing in another part of the same artery.
(2)
Explain why platelet inhibitors would reduce the risk of a heart attack.
(2)
any time the heart is mentoined, always make refence to coronary arteries and not just arteries.
Explain the role of antihypertensive drugs in reducing the risk of atherosclerosis.
(4)
State two possible side effects of taking drugs to reduce blood pressure.
(2)
Explain why beta-blockers are prescribed for some people.
(2)
Describe how high blood pressure could be reduced by medication and lifestyle
changes.
(3)
Explain the effect that a diet high in salt could have on a person’s risk of developing
cardiovascular disease.
(5)
