Download Free Medical Atheroma PowerPoint Presentation

Atheroma PowerPoint Presentation

DOWNLOAD MEDICAL POWERPOINT PRESENTATION

About This Presentation

Description : Check out this medical presentation on Aortic Aneurysm, which is titled "Atheroma", to know about atheroma and mechanisms of atherogenesis, etc.

Tags : Aortic Aneurysm, Atheroma, mechanisms

Published on : Jun 02, 2021 | Views : 2808 | Downloads : 1

Shareable Url :

Embed Code :

Comment

Transcript

Slide 1-

Leicester Warwick Medical School Atheroma Dr Mark Bamford Department of Pathology
Slide 2-

Atheroma - Objectives 1 Definition of atheroma Macroscopic appearances Microscopic appearances Effects
Slide 3-

Atheroma - Objectives 2 Mechanisms of atherogenesis encrustation insudation monoclonal response to injury Epidemiology Prevention/Intervention
Slide 4-

ppt slide no 4 content not found
Slide 5-

Atheroma Definition Atheroma is the accumulation of intracellular and extracellular lipid in the intima of large and medium sized arteries
Slide 6-

Atherosclerosis Definition The thickening and hardening of arterial walls as a consequence of atheroma
Slide 7-

Arteriosclerosis Definition The thickening of the walls of arteries and arterioles usually as a result of hypertension or diabetes mellitus
Slide 8-

Atheroma - Macroscopic Features Fatty streak Simple plaque Complicated plaque
Slide 9-

Atheroma - The Fatty Streak Lipid deposits in intima Yellow, slightly raised Relationship to atheroma somewhat debatable
Slide 10-

Atheroma - The Simple Plaque Raised yellow/white Irregular outline Widely distributed Enlarge and coalesce
Slide 11-

Atheroma - The Complicated Plaque Thrombosis Haemorrhage into plaque Calcification Aneurysm formation
Slide 12-

Atheroma - Common Sites Aorta - especially abdominal Coronary arteries Carotid arteries Cerebral arteries Leg arteries
Slide 13-

Normal Arterial Structure Endothelium Sub-endothelial c.t. Internal elastic lamina Muscular media External elastic lamina Adventitia
Slide 14-

Atheroma - Microscopic Features Early changes proliferation of smooth muscle cells accumulation of foam cells extracellular lipid
Slide 15-

Endothelium Smooth muscle cell Lipid Matrix
Slide 16-

Atheroma - Microscopic Features Later changes fibrosis necrosis cholesterol clefts +/- inflammatory cells
Slide 17-

Atheroma - Microscopic Features Later changes disruption of internal elastic lamina damage extends into media ingrowth of blood vessels plaque fissuring
Slide 18-

Atheroma - Coronary Artery
Slide 19-

Atheroma - Clinical Effects Ischaemic heart disease sudden death myocardial infarction angina pectoris arrhythmias cardiac failure
Slide 20-

Atheroma – myocardial infarction
Slide 21-

Atheroma – myocardial infarction
Slide 22-

Atheroma - Clinical Effects Cerebral ischaemia transient ischaemic attack cerebral infarction (stroke) multi-infarct dementia
Slide 23-

Atheroma – cerebral infarction
Slide 24-

Atheroma - Clinical Effects Mesenteric ischaemia ischaemic colitis malabsorption intestinal infarction
Slide 25-

Atheroma – intestinal infarction
Slide 26-

Atheroma - Clinical Effects Peripheral vascular disease intermittent claudication Leriche syndrome ischaemic rest pain gangrene
Slide 27-

Atheroma – peripheral vascular disease
Slide 28-

Atheroma – Abdominal Aortic Aneurysm
Slide 29-

Atheroma - Pathogenesis Age Gender Hyperlipidaemia Cigarette smoking Hypertension Diabetes mellitus Alcohol Infection
Slide 30-

Atheroma Age slowly progressive throughout adult life risk factors operate over years Gender women protected relatively before menopause presumed hormonal basis
Slide 31-

Atheroma Hyperlipidaemia high plasma cholesterol associated with atheroma LDL most significant HDL protective
Slide 32-

Atheroma - Lipid Metabolism Lipid in the blood is carried on lipoproteins Lipoproteins carry cholesterol and triglycerides (TG) Hydrophobic lipid core Hydrophilic outer layer of phospholipid and apolipoprotein (A-E)
Slide 33-

Atheroma - Lipid Metabolism Chylomicrons transport lipid from intestine to liver VLDL carry cholesterol and TG from liver TG removed leaving LDL LDL rich in cholesterol carry cholesterol to non-liver cells HDL carry cholesterol from periphery back to liver
Slide 34-

Atheroma and Apolipoprotein E Genetic variations in Apo E are associated with changes in LDL levels Polymorphisms of the genes involved lead to at least 6 Apo E phenotypes Polymorphisms can be used as risk markers for atheroma
Slide 35-

Familial Hyperlipidaemia Genetically determined abnormalities of lipoproteins Lead to early development of atheroma Associated physical signs arcus tendon xanthomas xanthelasma
Slide 36-

Xanthelasma
Slide 37-

Atheroma - Cigarette Smoking Powerful risk factor for IHD Risk falls after giving up Mode of action uncertain coagulation system reduced PGI2 increased platelet aggregation
Slide 38-

Atheroma - Hypertension Strong link between IHD and high systolic/diastolic blood pressure Mechanism uncertain ? endothelial damage caused by raised pressure
Slide 39-

Atheroma - Diabetes Mellitus DM doubles IHD risk Protective effect in premenopausal women lost DM also associated with high risk of cerebrovascular and peripheral vascular disease ?related to hyperlipidaemia and hypertension
Slide 40-

Atheroma - Alcohol Consumption >5 units /day associated with increased risk of IHD Alcohol consumption often associated with other risk factors eg smoking and high BP but still an independent risk factor Smaller amounts of alcohol may be protective
Slide 41-

Atheroma-Infection Chlamydia pneumoniae Helicobacter pylori Cytomegalovirus
Slide 42-

Atheroma - Other Risk Factors Lack of exercise Obesity Soft water Oral contraceptives Stress
Slide 43-

ppt slide no 43 content not found
Slide 44-

Atheroma - Genetic Predisposition Familial predisposition well known Possibly due to variations in apolipoprotein metabolism variations in apolipoprotein receptors
Slide 45-

Atheroma - Pathogenesis Thrombogenic theory Insudation theory Monoclonal hypothesis Reaction to injury hypothesis
Slide 46-

Atheroma - Thrombogenic Theory 1852 Karl Rokitansky plaques formed by repeated thrombi lipid derived from thrombi overlying fibrous cap
Slide 47-

Atheroma - Insudation Theory 1856 Rudolf Virchow endothelial injury inflammation increased permeability to lipid from plasma
Slide 48-

Atheroma - Reaction to Injury Hypothesis 1972 Ross and Glomset plaques form in response to endothelial injury hypercholesterolaemia leads to endothelial damage in experimental animals injury increases permeability and allows platelet adhesion monocytes penetrate endothelium smooth muscle cells proliferate and migrate
Slide 49-

Atheroma - Reaction to Injury Hypothesis 1986 Ross endothelial injury may be very subtle and be undetectable visually LDL, especially oxidised, may damage endothelium
Slide 50-

Atheroma - The Monoclonal Hypothesis Benditt and Benditt crucial role for smooth muscle proliferation each plaque is monoclonal might represent abnormal growth control is each plaque a benign tumour? could atheroma have a viral aetiology?
Slide 51-

Atheroma - The Processes Involved Thrombosis Lipid accumulation Production of intercellular matrix Interactions between cell types
Slide 52-

Atheroma - The Cells Involved Endothelial cells Platelets Smooth muscle cells Macrophages Lymphocytes Neutrophils
Slide 53-

Atheroma - Endothelial Cells Key role in haemostasis Altered permeability to lipoproteins Secretion of collagen Stimulation of proliferation and migration of smooth muscle cells
Slide 54-

Atheroma - Platelets Key role in haemostasis Stimulate proliferation and migration of smooth muscle cells (PDGF)
Slide 55-

Atheroma - Smooth Muscle Cells Take up LDL and other lipid to become foam cells Synthesise collagen and proteoglycans
Slide 56-

Atheroma - Macrophages Oxidise LDL Take up lipids to become foam cells Secrete proteases which modify matrix Stimulate proliferation and migration of smooth muscle cells
Slide 57-

Atheroma - Lymphocytes TNF may affect lipoprotein metabolism Stimulate proliferation and migration of smooth muscle cells
Slide 58-

Atheroma - Neutrophils Secrete proteases leading to continued local damage and inflammation
Slide 59-

Atheroma - A Unifying Hypothesis 1 Endothelial injury due to raised LDL ‘toxins’ eg cigarette smoke hypertension haemodynamic stress
Slide 60-

Atheroma - A Unifying Hypothesis 2 Endothelial injury causes platelet adhesion, PDGF release, SMC proliferation and migration insudation of lipid, LDL oxidation, uptake of lipid by SMC and macrophages migration of monocytes into intima
Slide 61-

Atheroma - A Unifying Hypothesis 3 Stimulated SMC produce matrix material Foam cells secrete cytokines causing further SMC stimulation recruitment of other inflammatory cells
Slide 62-

Atheroma and Apolipoprotein E Genetic variations in Apo E are associated with changes in LDL levels Polymorphisms of the genes involved lead to at least 6 Apo E phenotypes Polymorphisms can be used as risk markers for atheroma
Slide 63-

Atheroma - Prevention No smoking Reduce fat intake Treat hypertension Not too much alcohol Regular exercise/weight control BUT some people will still develop atheroma!
Slide 64-

Atheroma - Intervention Stop smoking Modify diet Treat hypertension Treat diabetes Lipid lowering drugs
Slide 65-

ppt slide no 65 content not found