Atheroma and Atherosclerosis Overview

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Questions and Answers

What is the primary component of the soft, yellow core of an atheroma?

Fatty acids

Triglycerides

Cholesterol esters (correct)

Phospholipids

Which statement best describes arteriosclerosis?

It solely affects small arteries.

It represents a specific type of atherosclerosis.

It is characterized by the accumulation of plaque in the arteries.

It involves the thickening and loss of elasticity of arterial walls. (correct)

Which of the following is NOT a cellular event leading to atherosclerotic lesions?

Inflammatory response

Vasoconstriction of small arteries (correct)

Formation of fibrous cap

Accumulation of lipids

What role do cytokines such as platelet-derived growth factor (PDGF) play in atherogenesis?

They promote inflammation and cell proliferation. Signup and view all the answers

Which of the following is considered a risk factor for atherogenesis?

Hypertension Signup and view all the answers

What characterizes Mönckeberg medial calcific sclerosis?

Calcific deposits in muscular arteries Signup and view all the answers

Which cell type is primarily involved in the initial stages of atherosclerotic lesion formation?

Endothelial cells Signup and view all the answers

Which of the following processes is NOT involved in the formation of atheroma?

Increased oxygenation of tissues Signup and view all the answers

What is the primary function of macrophages in atheroma formation?

Oxidize LDL and become foam cells Signup and view all the answers

Which of these motifs describes the composition of fatty streaks in atherosclerosis?

Dominated by lipid-filled foam cells Signup and view all the answers

Which role do smooth muscle cells play in the context of vascular injury?

They proliferate and migrate to form a neointima. Signup and view all the answers

What stimulates the proliferation and migration of smooth muscle cells during atheroma formation?

Platelet-derived growth factor (PDGF) Signup and view all the answers

Which morphological appearance is associated with the earliest stage of atherosclerosis?

Fatty streaks Signup and view all the answers

Which condition is caused by the accumulation of lipoproteins in the arterial wall?

Atherosclerosis Signup and view all the answers

What are the primary sites of development for atherosclerotic plaques?

Elastic arteries and large muscular arteries Signup and view all the answers

What is the most significant type of lipoprotein associated with atheroma formation?

LDL Signup and view all the answers

Which of the following is a major consequence of atherosclerosis?

Peripheral vascular disease Signup and view all the answers

Which of the following is a protective lipoprotein against atheroma?

HDL Signup and view all the answers

What is the term for early changes in atherosclerosis characterized by smooth muscle proliferation?

Proliferation of smooth muscle cells Signup and view all the answers

What is the primary reason women experience relatively lower atheroma risk before menopause?

Hormonal protection Signup and view all the answers

Which factor significantly increases the risk of ischemic heart disease (IHD)?

High plasma cholesterol Signup and view all the answers

During the progression of atheromas, which of the following is considered a late change?

Cholesterol clefts Signup and view all the answers

What is a key feature of complicated plaques?

Presence of thrombosis Signup and view all the answers

What is a common complication associated with chronic hypertension?

Aneurysm formation Signup and view all the answers

Which condition is caused by atherosclerosis affecting coronary arteries?

Ischaemic heart disease Signup and view all the answers

Which of the following is not typically a risk factor for atheroma formation?

Regular physical exercise Signup and view all the answers

Fatty streaks can be found in the aortas of children older than what age?

Older than 10 years Signup and view all the answers

Which hypothesis views atherosclerosis as a chronic inflammatory response to endothelial injury?

Response-to-injury hypothesis Signup and view all the answers

The accumulation of foam cells in atherosclerosis is primarily due to the activity of what type of cell?

Macrophages Signup and view all the answers

Which factor is not typically associated with the development of endothelial dysfunction?

High levels of HDL cholesterol Signup and view all the answers

What is a primary consequence of endothelial injury in atherosclerosis?

Platelet adhesion and PDGF release Signup and view all the answers

Which lifestyle modification is least effective in preventing atheroma?

Increasing saturated fat intake Signup and view all the answers

Which of the following is a common risk factor for Coronary Heart Disease (CHD)?

Smoking Signup and view all the answers

What role do foam cells play in atheromas?

Secrete cytokines promoting inflammation Signup and view all the answers

Which of the following is not an etiologic factor contributing to early atherosclerosis?

Low vitamin D levels Signup and view all the answers

Which condition is characterized by increased risk of ischemic heart disease due to high blood sugar levels?

Diabetes mellitus Signup and view all the answers

Which lipoprotein abnormality is typically associated with myocardial infarction survivors?

Increased LDL cholesterol levels Signup and view all the answers

Study Notes

Atheroma, Atherosclerosis, Arteriosclerosis

Atheroma is the accumulation of intracellular and extracellular lipid in the intima and media of large and medium-sized arteries.
Atheroma forms a raised, focal lesion within the intima, with a soft, yellow lipid core (mainly cholesterol) covered by a firm, white fibrous tissue.
Arteriosclerosis is a general term for thickening and loss of arterial wall elasticity.
Three types of arteriosclerosis exist: atherosclerosis, Mönckeberg medial calcific sclerosis (calcification in muscular arteries after age 50), and arteriolosclerosis (affects smaller arteries and arterioles).

Intended Learning Outcomes

Understanding definitions of atheroma, atherosclerosis, and arteriosclerosis.
Knowledge of cellular processes leading to atherosclerotic lesions.
Awareness of the macroscopic and microscopic appearances of atheromas.
Effects of severe atherosclerosis at specific anatomical sites.
Mechanisms of atherogenesis, including the role of growth factors, cytokines (e.g., platelet-derived growth factor [PDGF]), the response to injury hypothesis, and dyslipidaemias.
Epidemiology of coronary heart disease, including description of the role of coronary risk factors in atherogenesis and genetic, geographic, and ethnic susceptibility.

Cells Involved in Atheroma Formation

Endothelial cells
Smooth muscle cells
Macrophages
Platelets
Neutrophils
Lymphocytes

Cellular Events Leading to Atherosclerotic Lesions (Endothelial Cells)

Play a key role in haemostasis, modulating blood flow and vascular resistance.
Exhibit altered permeability to lipoproteins.
Secrete collagen.
Stimulate proliferation and migration of smooth muscle cells.
Loss of endothelial cells (denudation) triggers thrombosis and smooth muscle cell proliferation.

Vascular Smooth Muscle Cells

Migrate to intima and proliferate following vascular injury.
Crucial in normal vascular repair and pathological processes such as atherosclerosis.
Take up LDL and other lipids, transforming into foam cells.
Synthesize collagens and proteoglycans.
Vascular injury triggers smooth muscle cell growth and formation of a neointima.

Lymphocytes

TNF may affect lipoprotein metabolism.
Stimulate smooth muscle cell proliferation and migration.

Platelets

Key role in haemostasis.
Stimulate smooth muscle cell proliferation and migration (e.g., PDGF).

Macrophages

Oxidize LDL, taking up lipid to become foam cells.
Secrete proteases to modify the matrix.
Stimulate smooth muscle cell proliferation and migration.

Processes Involved in Atheroma Formation

Thrombosis
Lipid accumulation.
Production of intercellular matrix.
Interactions between different cell types.

Nomenclature and Main Histology of Atheroma

Different stages of atheroma development are detailed, with specific histological descriptions & types (e.g., Type I, Type II, Type III, etc.).
Progression of lesions, categorized by factors such as growth mechanism, earliest onset, and correlation with clinical presentation are indicated.

Morphological Appearance of Atheroma

Fatty streaks: initial lesion of atherosclerosis, composed of lipid-filled foam cells.
Simple plaque: raised yellow/white, irregular, widely distributed, and coalesced.
Complicated plaque: advanced lesion features, including thrombosis, hemorrhage, calcification, and aneurysm formation.

Atherosclerotic Plaques

Develop primarily in elastic arteries and large/medium-sized muscular arteries.
Leading consequences include myocardial infarction, stroke, aortic aneurysms, and peripheral vascular disease.
Other consequences include mesenteric occlusion, sudden cardiac death, chronic ischemic heart disease, and ischemic encephalopathy.

Effects of Severe Atherosclerosis at Specific Sites

Coronary artery disease, ischemic heart disease, sudden death, myocardial infarction, angina pectoris, arrhythmias, and cardiac failure.
Cerebral ischaemia, transient ischaemic attack, cerebral infarction, multi-infarct dementia.
Mesenteric ischaemia, ischemic colitis, malabsorption, intestinal infarction.
Peripheral vascular disease, intermittent claudication, Leriche syndrome, ischemic rest pain, gangrene..

Risk Factors for Atheroma

Age: slowly progressive from adulthood, women generally protected until menopause.
Hyperlipidaemia: high plasma cholesterol is strongly linked to atheroma, with LDL cholesterol being a major factor.
Hypertension: strong link; endothelial damage is a consequence.
Smoking: significant risk factor.
Diabetes Mellitus: doubles risk of IHD.
Alcohol: high consumption increases IHD risk.
Infection (e.g., Helicobacter pylori): recent evidence indicates an association.

Risk Factors (Continued)

Specific genetic disorders, Family Hypercholesterolemia.
Geographical factors, often influenced by diet.
Ethnicity, with higher risk in some groups
Other risk Factors: homocysteine, toxins from cigarettes.

Pathogenesis (Response-to-Injury Hypothesis)

Atherosclerosis is a chronic inflammatory and healing response to arterial wall injury.
Lesion progression is connected to the interaction of modified lipoproteins, macrophage, and T lymphocytes with normal arterial wall structure.
Endothelial injury leads to increased vascular permeability, leukocyte adhesion, and thrombosis; leading to lipoprotein accumulation, especially oxidized LDL cholesterol.

Prevention of Atheroma

Modification of established risk factors.
Lifestyle changes, such as stop smoking, diet modification, treatment of hypertension, and diabetes, along with lipid-lowering drugs.
Treating genetic predisposition, such as familial hypercholesterolemia..

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Description

This quiz covers the definitions and characteristics of atheroma, atherosclerosis, and arteriosclerosis. It also explores the cellular processes involved in atherogenesis and the implications of severe atherosclerosis on anatomical sites. Test your understanding of these important cardiovascular concepts.