Unit 2 (K7) - Pathology of Cardiovascular Disease Flashcards
Describe what happens in atherosclerosis.
- The accumulation of fatty material (consisting of mainly cholesterol), fibrous material and calcium forms an atheroma or plaque beneath the endothelium.
- As the atheroma grows the artery thickens and loses elasticity.
- The diameter of the artery becomes reduced and blood flow becomes restricted resulting in increased blood pressure.
Which diseases are caused by atherosclerosis?
- Angina
- Heart Attack
- Stroke
- Peripheral Vascular Disease
What is thrombosis?
The formation of blood clots.
How can atherosclerosis lead to thrombosis?
- An atheroma can damage the artery endothelium.
- This releases clotting factors and a cascade of reactions are triggered leading to conversion of prothrombin and thrombin.
- Thrombin causes plasma protein fibrinogen to form threads of fibrin.
- Fibrin forms a thrombus (blood clot).
How can thrombosis cause a heart attack?
- A thrombus (blood clot) formed on an atheroma can break loose creating an embolus and this travels through the blood stream until it blocks a blood vessel.
- If the vessel blocked is a coronary artery then this may lead to a heart attack (myocardial infarction).
- Cells are deprived of oxygen leading to death of tissues.
How can thrombosis lead to a stroke?
- A thrombus (blood clot) formed on an atheroma can break loose creating an embolus and this travels through the blood stream until it blocks a blood vessel.
- If the blood vessel blocked is in the brain then this may lead to a stroke.
- Cells are deprived of oxygen leading to death of tissues.
What is Peripheral Vascular Disease?
This is the narrowing of the arteries due to atherosclerosis of arteries other than those in the heart or brain.
What are symptoms of Peripheral Vascular Disease?
- Pain when walking (usually the legs are involved) due to limited supply in oxygen.
What is Deep Vain Thrombosis (DVT)?
- The formation of a thrombus in the lower part of the leg in the deep vein resulting in swelling and severe pain.
Why can DVT in the leg be fatal?
If the thrombus breaks free to create an embolus this can travel to the pulmonary artery where it can cause a blockage, resulting in chest pain and breathing difficulties. If untreated, this can lead to death.
What is cholesterol and where in the body is it found?
It is a type of lipid found in the cell membrane.
As well as being a component of the cell membrane, what else is cholesterol used for in the body?
To make sex hormones, testosterone, oestrogen and progesterone.
Where does cholesterol in our bodies come from?
- Cholesterol is synthesised by all cells.
- 25% of it is made in the liver.
- A diet high in saturated fats or cholesterol cases an increase in cholesterol levels in the blood.
What are HDLs and what do they do?
- High Density Lipoproteins.
- They carry cholesterol from the body cells to the liver.
- High levels of HDL in the blood reduce cholesterol in plaques in the artery walls.
What are LDLs and what do they do?
- Low density lipoproteins.
- They carry cholesterol from the liver to the body cells.