Atheroma Formation and Atherosclerosis Flashcards
(20 cards)
What is an atheroma?
An atheroma is the abnormal accumulation of fatty material (mainly cholesterol) in the inner wall (intima) of medium-sized and large arteries. It leads to the thickening and hardening of the arterial walls and is also known as an atherosclerotic lesion.
What diseases are associated with atheroma formation in different arteries?
Coronary arteries: Coronary artery disease, angina (chest pain), and myocardial infarction (heart attacks).
Cerebral arteries: Cerebrovascular disease, including transient ischemic attack (TIA) and stroke.
Peripheral arteries: Peripheral vascular disease, claudication (pain in the lower limbs during walking), and gangrene (due to lower limb ischemia).
What is atherosclerosis and why is it significant?
Atherosclerosis is a chronic inflammatory and healing response of the arterial wall to endothelial injury. It is the leading cause of cardiovascular disease, which is the number one cause of death and disability worldwide.
What are the modifiable risk factors for atherosclerosis?
High blood pressure
High cholesterol
Type 2 diabetes
Obesity
Lack of exercise
Smoking
What are the non-modifiable risk factors for atherosclerosis?
Age
Ethnicity
Gender
Family history
How do high LDL and HDL levels affect heart health?
High levels of LDL (low-density lipoprotein, often called “bad” cholesterol) are associated with a higher risk of heart disease. HDL (high-density lipoprotein, known as “good” cholesterol) helps to remove cholesterol from the bloodstream, reducing heart disease risk.
What is the first step in the progression of atherosclerosis?
The first step is endothelial dysfunction, where there is decreased production of nitric oxide, leading to increased permeability and disruption of the endothelial lining of the artery.
How does endothelial injury contribute to atherosclerosis?
Endothelial injury initiates an inflammatory response in the arterial wall, leading to increased expression of adhesion molecules. Monocytes attach to the injured area and migrate into the vessel wall, contributing to the formation of an atheroma.
What is the role of cholesterol in the development of atherosclerosis?
LDL cholesterol enters the vessel wall, where it is taken up by monocytes, which become macrophages. These macrophages transform into foam cells, leading to the accumulation of fatty streaks and an inflammatory response involving T lymphocytes.
What is the fibrous cap, and how does it form in atherosclerosis?
The fibrous cap forms as part of the inflammatory response. Cytokines and growth factors released by macrophages, platelets, and endothelial cells promote the proliferation and migration of smooth muscle cells, leading to the formation of a fibrous cap that overlays the fatty core of the plaque.
What happens during plaque rupture in atherosclerosis?
When the fibrous cap of an atherosclerotic plaque ruptures, the fatty core is exposed to the bloodstream, triggering the coagulation cascade. This leads to platelet activation and the formation of a thrombus (blood clot), which can obstruct the artery.
What is the difference between stenotic and non-stenotic lesions in atherosclerosis?
Stenotic lesions have a thick fibrous cap, are stable, and contain fewer immune cells.
Non-stenotic lesions have a thin fibrous cap, are unstable, and contain many immune cells, making them more likely to rupture.
What are the main treatment principles for atherosclerosis?
To prevent or manage atherosclerosis, the following treatments are commonly used:
Hyperlipidaemia: Lipid-lowering drugs such as statins.
Hypertension: Anti-hypertensive drugs to lower blood pressure.
Diabetes: Medications to lower blood sugar.
Smoking: Smoking cessation programs.
Additionally, obstructed arteries can be treated with interventions like stents and thrombolysis.
How can modifiable risk factors for atherosclerosis be managed?
Modifiable risk factors can be managed through lifestyle changes such as regular exercise, a healthy diet, smoking cessation, weight management, and medication to control blood pressure, cholesterol levels, and blood sugar.
What role do immune cells play in the progression of atherosclerosis?
Immune cells, particularly monocytes and macrophages, play a key role in the progression of atherosclerosis. Monocytes migrate into the arterial wall after endothelial injury and transform into macrophages. These macrophages then become foam cells, contributing to the accumulation of fatty material and inflammation, which leads to the formation and growth of plaques.
What is the significance of the fibrous cap in an atherosclerotic plaque?
he fibrous cap serves to stabilize the plaque and prevent its rupture. It forms as a result of smooth muscle cell proliferation and migration, driven by cytokines and growth factors released by macrophages, platelets, and endothelial cells. A thicker fibrous cap is associated with a more stable plaque, while a thinner cap increases the risk of rupture.
What is a thrombus, and how is it related to atherosclerosis?
A thrombus is a blood clot that forms when the fibrous cap of an atherosclerotic plaque ruptures. The exposure of the fatty core to the bloodstream activates platelets and initiates the coagulation cascade, leading to clot formation. A thrombus can obstruct the artery, leading to conditions such as heart attack or stroke.
Why are LDL cholesterol levels considered a major risk factor for atherosclerosis?
High levels of LDL cholesterol (low-density lipoprotein) are a major risk factor for atherosclerosis because LDL particles are prone to accumulate in the walls of arteries. This leads to the formation of fatty streaks, inflammation, and the development of plaques, which can narrow the arteries and reduce blood flow.
What lifestyle changes can help manage obesity as a risk factor for atherosclerosis?
Managing obesity involves adopting a balanced diet, engaging in regular physical activity, and possibly seeking medical or professional guidance. Reducing body fat can improve blood pressure, cholesterol levels, and insulin sensitivity, all of which contribute to a lower risk of atherosclerosis.
How does atherosclerosis lead to peripheral vascular disease?
Atherosclerosis in the peripheral arteries, particularly those in the lower limbs, leads to peripheral vascular disease (PVD). As plaques build up in these arteries, they narrow and obstruct blood flow, leading to symptoms such as claudication (pain in the legs during walking) and, in severe cases, gangrene due to insufficient blood supply to the tissues.
