Pathology of cvd Flashcards
What is arteriosclerosis?
- A thickening and hardening of the walls of the arteries, occurring typically in old age
What is atherosclerosis?
A disease of the arteries characterised by the deposition of fatty materials (cholesterol) on the inner walls
What are 3 examples of ‘non-modifiable factors’?
- Genes
- Gender
- Age
The development of atherosclerosis in people is multifactorial. What does it consist of?
- Non-modifiable factors and lifestyle choices (modifiable factors)
What is the most important risk factor of atherosclerosis?
Hyperlipidaemia (elevated levels of lipids in the blood plasma)
What is the process of atherosclerosis?
- A chronic inflammatory process followed by the healing response
- Inflammatory process as cholesterol is deposited in the BV walls (inflammatory reaction of the chronic type)
- Then healing process - but does not actually heal (you get the response but you don’t get the healting)
What does atherosclerosis cause the formation of?
- An atheroma
What is an atheroma?
- A fatty, fibrous thickening of an artery
What 2 things can a vascular pathology be?
Either a stenosis/obstruction or the weakening of the walls leading to dilation/rupture
What is a stenosis?
- An abnormal narrowing of blood vessels
When are females at a higher risk of developing atherosclerosis?
- After menopause - before the onset of menopause women have a lower risk due to BV having a higher level of oestrogen that ensures the BV stays open, however after menopause oestrogen levels decline
What is familial hypercholesterolaemia?
- Autosomal dominant condition
- Mutation of the LDL receptor gene (low density lipoprotein receptor gene, many cells in the liver have this receptor in the membrane)
- Cells take up cholesterol from the blood and process it in the liver, if they have one normal gene and one non-functioning gene then they have 50% increase in bad blood cholesterol
- If they have complete wrong protein have to go on statins as early as possible as at high risk
Where are LDL receptors found?
- Present in many cell types including smooth muscle cells, fibroblasts and adrenocortical cells
What is the chronic inflammation stage of atheroma’s? (5 points)
- Chronic inflammatory response to lipoproteins
- Endothelial cells change surface cell receptors and become more permeable to lipids
- Change cells adhesion molecules for monocytes so attach to endothelium and move into blood vessel walls
- Monocytes include macrophages and T-cells
- Foam cells, lipid deposits from dead cells
What is a foam cell?
- A foam cell is a specialised type of cell created by white blood cells. Initially a waste removal cell type called a macrophage, the foam cell specifically targets cholesterol and fat build up in the blood cells. Once it has ingested these substances, it assumes a foam like texture and appearance, thereby crating its name
What is the healing response phase of atheroma formation? (7 points)
- Proliferation of smooth muscle cells
- Fibrous tissue formation
- Growth factors such as PDGF, FGF, TGF-alpha, are produced
- A fibro-fatty plaque is formed with a central mass of lipid and necrotic tissue
- Neovascularization may be seen at the periphery of the plaque
- Haemorrhage can occur into the plaque
- Calcification of the lipid and necrotic tissue may sometimes occur
What is neovascularisation?
- New blood vessel formation in abnormal tissue or in abnormal positions
What is the overall process of atheroma formation? (5 main points)
- Chronic endothelial cell injury - may be genet ic mutation, inherited, hypertension etc
- PErmeability increases. Lipid is deposited in the intimal layers
- Macrophages move in - foam cells, fatty streaks - these may regress if you reduce the risk factors
- Smooth muscles proliferation. MAcrophages produce IL-1 which activates T-cells. More cytokines, chemokines, ROS activate more inflammatory cells PLGF, FGF, TGF-alpha
- Healing phase - fibrous tissue formation, over the lipid and a fibro fatty atheroma if formed (plaque)
- Dystrophic calcification may occur at late stages
What are fatty streaks?
- Early evidence of atherosclerosis, macrophages and smooth muscle cells accumulate in the intima of arteries?
What are 4 examples of effects atherosclerosis can have?
- Decreased blood supply to tissue/organ (ischaemia)
- Complete occlusion of the blood vessel leading to infarction
- Thrombosis
- Embolism
What is infarction?
- Obstruction of the blood supply of an organ or region of tissue, causing local death of the tissue
What is thrombosis?
When a blood clot forms within a blood vessel and prevents the proper flow of blood around the circulatory system
What is an embolism?
- An obstruction in a blood vessel due to a blood clot or other foreign matter that gets stuck while travelling through the bloodstream
Is chronic periodontitis related to atherosclerosis and CVD
- There is a theory that chronic periodontitis can cause atherosclerosis
- When a person has CP they have chronic inflammation and lots of factors that are released as a result of this - they are released into the circulation where they travel to the liver and cause an acute phase response which can cause atherosclerosis
- Still don’t know if this is absolutely true
What 4 things can peripheral vascular disease cause?
- Ischaemia
- Claudication
- Gangrene
- Coagulation necrosis +infection
What is claudication?
- A condition in which cramping pain in the leg is induced by exercise, typically caused by an obstruction of the arteries
What is gangrene?
- Death of the body tissues due to ischaemia
Who is predisposed to gangrene?
- Diabetics
What is coagulation necrosis?
- A condition of cell death that is caused by a lack of blood flow
What is an aneurism?
- An abnormal dilation in the wall of an artery supplying blood to a specific area
- Can occur in blood vessels or in the cardiac wall as well as other places in the body
What are 3 examples of factors that can cause an aneurism?
- Developmental
- Degenerative
- Traumatic
What is the most common type of aneurism and what does this result from?
- AAA’s (abnormal aortic aneurisms)
- Results from atherosclerosis
What do aneurisms play a role in?
- Peripheral vascular disease