KA7 Pathology of cardio vascular disease Flashcards
What is the process of atherosclerosis?
Atherosclerosis is the accumulation of fatty material (consisting of mainly cholesterol, fibrous material and calcium) forming an ATHEROMA or plaque beneath the endothelium in the wall of an artery.
What happens as the atheroma grows?
The artery thickens and looses its elasticity.
The diameter of the lumen becomes reduced and blood flow becomes restricted. This results in INCREASED blood pressure.
What is atherosclerosis the root cause of?
Various cardio vascular diseases including angina, heart attack, stroke and peripheral vascular disease.
What happens when an atheroma ruptures? (Thrombosis)
Atheroma may rupture damaging the endothelium. The damage releases clotting factors that activate a cascade of reactions resulting in the conversion of the enzyme prothrombin into its active form thrombin.
What happens to thrombin? (Thrombosis)
Thrombin causes molecules of the soluble plasma protein FIBRINOGEN to form threads of insoluble fibrin. The fibrin threads form a meshwork that clots the blood, seals the wound and provides a scaffold for the formation of scar tissue.
The formation of a clot (thrombus) is referred to as thrombosis.
What is the formation of fibrin?
Prothrombin + Clotting factors = Thrombin
Thrombin + Fibrinogen = Fibrin
What happens if a thrombus (blood clot) breaks loose?
If a thrombus breaks loose it is known as an embolus.
It travels through the bloodstream until it blocks a blood vessel.
What happens if thrombosis occurs in the coronary artery/ in the brain?
Coronary artery- myocardial infraction (MI) aka a heart attack
Brain- stroke
What happens to tissues in areas that are deprived of blood due to blockages causes by thrombosis?
Cells are deprived of oxygen leading to deaths of tissues.
What is peripheral vascular disease?
The narrowing of the arteries due to the atherosclerosis of arteries other than those in the heart or brain. The arteries to the legs are most commonly affected. Pain is experienced in the leg muscles due to a limited supply of oxygen.
What is deep vein thrombosis (DVT)?
DVT is a blood clot that forms in a deep vein, most commonly in the leg. If the clot breaks off and travels through the bloodstream to the lungs it may result in a pulmonary embolism. This can lead to collapse and sudden death.
What is cholesterol and what is it good for?
Cholesterol is a type of lipid found in the cell membrane. It is also used to make the sex hormones- testosterone, oestrogen and progesterone
What cells synthesis cholesterol?
Cholesterol is synthesised by all cells although 25% of total production takes place in the liver.
What causes an increase in cholesterol levels in the blood?
A diet high in saturated fats or cholesterol
What are the two types of cholesterol?
High density lipoproteins HDL (good)
Low density lipoproteins LDL (bad)
