Session 6 Athersclerosis Flashcards
What is atherosclerosis?
The accumulation of intracellular and extracellular lipid in the intima and media of large and medium sized arteries.
What are the macroscopic features of atherosclerosis?
Fatty streak
- lipid deposits, yellow, slightly raised.
Simple plaque
- irregular outline, praised yellow/white, widely distributed
Complicated plaque
- thrombosis, haemorrhage into plaque, calcification, aneurysm formation
What are the common sites of atherosclerosis ?
- aorta, especially abdominal
- coronary arteries
- carotid arteries
- cerebral arteries
- leg arteries.
What are the 3 layers of arteries and veins?
Tunica intima
Tunica media
Tunica externae/Adventita
What later changes may occur to microscopic features to atherosclerosis?
- fibrosis
- necrosis
- cholesterol clefts
- less/more inflammatory cells
- disruption of internal elastic lamina
- plaque fissuring
What are the clinical effects of atherosclerosis?
Ischaemic heart disease
- angina pectoris
- arrhythmia
- cardiac failure
- sudden death
- MI
Cerebral ischaemia
- cerebral infarction
- multi infarct dementia
- transient ischaemic attack
Mesenteric ischaemia
- intestinal infarction
- malabsorption
- ischaemic colitis
Peripheral vascular disease
- intermittent claudication
- gangrene
- ischaemic rest pain
What’s the pathogenesis of atherosclerosis?
1) Age = older, more at risk
2) Gender = women more protected before menopause
3) Hyperlipidaemia = high plasma cholesterol associated with atherosclerosis, LDL most significant, HDL protected
What is the role of chylomicrons?
Transport lipid From intestine To liver
What’s the role of LDL?
Carry cholesterol to non liver cells
What’s the role of VLDL?
Carry cholesterol and TG to liver, TG removed = leaving LDL
What’s the role of HDL?
Carry cholesterol from periphery back to liver
What are the associated signs of hyperlipidaemia ?
- corneal Arcus
- tendon xanthomas
- xanthelasma
Risk factors for atherosclerosis?
Smoking
- increase platelet aggregation, also risk for ischaemic heart disease
Hypertension
- risk for Ischaemic heart disease, endothelial damage done by raised pressure
Diabeties mellitus
- doubles IHD risk, protective in premenopausal women
Alcohol
- associated with IHD
Infection Lack of exercise Obesity Soft water Oral contraceptives
What cells are involved in atherosclerosis?
Endothelial cells Platelets Smooth muscle cells Macrophages Lymphocytes Neutrophils
What’s the role of macrophages?
Oxides LDL
Take up lipids to become foam cells
Secrete protease which modify matrix
