Pathology of Cardiovascular Disease (CVD) Flashcards
What is Atherosclerosis?
The accumulation of fatty material (consisting mainly of cholesterol), fibrous material and calcium, forming an atheroma or plaque.
Where does an atheroma form?
Beneath the endothelium of the artery wall.
What does an atheroma do?
As an atheroma grows, the artery thickens and loses its elasticity. An atheroma reduces the diameter of the lumen of an artery, which restricts blood flow and results in increased blood pressure.
What is Atherosclerosis the root cause of?
Various cardiovascular diseases including angina, heart attack, stroke and peripheral vascular disorders.
What happens if an atheroma ruptures?
The damage to the endothelium causes the release of clotting factors. Clotting factors cause the enzyme prothrombin to be converted into its active form thrombin.
What does thrombin do?
Causes molecules of the soluble plasma protein fibrinogen to form threads of insoluble fibrin protein.
What happens to Fibrin during Thrombosis?
Fibrin threads form a mesh work that platelets adhere to, forming a blood clot which seals a wound and provides a scaffold for the formation of scar tissue.
What is thrombosis?
The formation of a blood clot (thrombus) in a vessel.
What happens if a thrombus breaks loose?
It forms an embolus that travels through the bloodstream until it blocks a blood vessel.
What may happen f thrombosis occurs in a coronary artery?
A myocardial infarction (heart attack).
What may happen if thrombosis in an artery in the brain occurs?
A stroke.
What does thrombosis normally result in?
The death of some of the tissue served by the blocked artery as the cells are deprived of oxygen.
What are peripheral vascular disorders?
Narrowing of arteries due to Atherosclerosis of arteries other than those of the heart and brain.
What can blood clots result in?
Deep Vein Thrombosis (DVT) and pulmonary embolism.
What is DVT?
The formation of a blood clot in a deep vein, most commonly in the lower part of the leg. In DVT, pain is experienced in the leg muscles due to a limited supply of oxygen.
How is a pulmonary embolism caused?
Part of an thrombus breaking free and travelling through the bloodstream to the pulmonary artery where it can cause blockage, resulting in chest pain and breathing difficulties.
What is cholesterol?
A component of cell membranes and a precursor for steroid synthesis.
How is most cholesterol synthesised?
By the liver from saturated fats in the diet.
What do lipoproteins contain?
Lipid and protein.
What does High Density Lipoprotein (HDL) do?
Transports excess cholesterol from the body cells to the liver for elimination and so prevents the accumulation of cholesterol in the body.
What does Low Density Lipoprotein (LPD) do?
Transports cholesterol to body cells. Most cells have LDL receptors that take LDL into the cell, where it releases cholesterol.
What happens once a cell has sufficient cholesterol?
A negative feedback system inhibits the synthesis of new LDL receptors and so LDL circulated in the blood where is may deposit the cholesterol in the arteries, forming atheromas.
How is Familial Hypercholesterolaemia (FH) caused?
By an autosomal dominant allele that results in individuals developing high levels of cholesterol.
