Cardiovascular COPY Flashcards
Define atherosclerosis.
A hardened plaque in the intima of an artery. It is an inflammatory process.
What can an atherosclerotic plaque cause?
- Heart attack.
- Stroke.
- Gangrene.
What are the constituents of an atheromatous plaque?
- Lipids.
- Necrotic core.
- Connective tissue.
- Fibrous cap.
- Lymphocytes
- Foam cell
Give 5 risk factors for atherosclerosis.
- Family history.
- Increasing age.
- Smoking.
- High levels of LDL’s.
- Obesity.
- Diabetes.
- Hypertension.
In which arteries would you be most likely to find atheromatous plaques?
In the peripheral and coronary arteries.
Which histological layer of the artery may be thinned by an atheromatous plaque?
The tunica media due to migration of smooth muscle cells into the plaque
What is the precursor for atherosclerosis.
Fatty streaks.
What can cause chemoattractant release?
A stimulus such as endothelial cell injury.
How does injury to endothelial cells cause atherosclerosis
- Injury ➡️ endothelial dysfunction ➡️ chemoattractants released from endothelial cells signal circulating leukocytes
- chemoattractants are released from the site of injury ➡️ conc. gradient which the leukocytes follow.
- this causes leukocytes accumulation and they migrate into the vessel wall ➡️ inflammation
Describe the process of leukocyte recruitment.
- Capture.
- Rolling.
- Slow rolling.
- Adhesion.
- Trans-migration.
Describe in 5 steps the progression of atherosclerosis.
- Fatty streaks.
- consist of lipid-laden macrophages [foam cells] + T-lymphocytes within the intima layer
- Intermediate lesions.
- made of layers of foam cells, vascular smooth muscles cells + T-lymphocytes
- Fibrous plaque.
- covered by fibrous cap that is made of collagen and elastin for strength and flexibility.
- Plaque rupture.
- the fibrous cap is resorbed and redeposited in order to be maintained
- Plaque erosion.
- Second most prevalent cause of coronary thrombosis
Progression of atherosclerosis: what are the constituents of fatty streaks?
Foam cells and T-lymphocytes. Fatty streaks can develop in anyone from about 10 years old.
Progression of atherosclerosis: what are constituents of intermediate lesions?
- Foam cells.
- Smooth muscle cells.
- T lymphocytes.
- Platelet adhesion.
- Extracellular lipid pools.
Progression of atherosclerosis: what are the constituents of fibrous plaques?
- Fibrous cap overlies lipid core and necrotic debris.
- Smooth muscle cells.
- Macrophages.
- Foam cells.
- T lymphocytes.
Fibrous plaques can impede blood flow and are prone to rupture.
Progression of atherosclerosis: why might plaque rupture occur?
- Fibrous plaques are constantly growing and receding.
- The fibrous cap has to be resorbed and redeposited in order to be maintained.
- If balance shifted in favour of inflammatory conditions, the cap becomes weak and the plaque ruptures –> Thrombus formation and vessel occlusion.
- e.g. infection tips the balance
What is the treatment for atherosclerosis?
Percutaneous coronary intervention (PCI).
What is the major limitation of PCI?
Restenosis.
reduction in lumen diameter again
How can restenosis be avoided following PCI?
Drug eluting stents: anti-proliferative and prevent scar formation.
drugs that inhibit healing.
What is the key principle behind the pathogenesis of atherosclerosis?
It is an inflammatory process!
Define atherogenesis.
The development of an atherosclerotic plaque.
Define angina.
- Angina is a type of IHD.
- It is a symptom of O2 supply/demand mismatch to the heart experienced on exertion.
- narrowed lumen of coronary arteries reduces blood flow to the cardiomyocytes –> ischaemia.
What is the most common cause of angina?
Narrowing of the coronary arteries due to atherosclerosis.
Give 5 possible causes of angina.
- Narrowed coronary artery = impairment of blood flow e.g. atherosclerosis.
- LV hypertrophy –> increased O2 demands.
- Reduced O2 carrying capacity e.g. anaemia.
- Coronary artery spasm.
- Thrombosis.
Give 5 modifiable risk factors for angina.
- Smoking.
- Diabetes.
- High cholesterol (LDL).
- Obesity/sedentary lifestyle.
- Hypertension.