Atheroma, Thrombosis and Embolism

Question 1

what is atheroma

Answer 1

lesion in the intimate layer of blood vessel raised via lipids (cholesterol and esters) and covered by a fibrous cap

Question 2

what is atherosclerosis

Answer 2

hardening of the blood vessels due to atheroma formation

Question 3

which types of arteries are commonly affected by atheroma

Answer 3

bifurcations (sites of turbulent flow) 
abdominal aorta
coronary arteries
popliteal arteries 
carotid arteries 
circle of willis

Question 4

what are the major risk factors of atheroma formation

Answer 4

non-modifiable - increasing age, male gender, history, genetic s

modifiable - hyperlipidemia, hypertension, C reactive protein (damage vessel walls)

Question 5

why does atherosclerosis develop

Answer 5

in response to endothelial injury and develops as a chronic inflammatory response in the arterial wall

Question 6

what is the response to injury hypothesis in atheroma formation

Answer 6

chronic endothelial damage - margination of cells along endothelium - initiates increased vascular permeability

accumulation of lipoproteins in th eintima (high LDL levels)
monocyte adhesion to endothelium, proliferation and ECM production
factor release - recruitment of inflammatory cells

Question 7

describe the morphological evolution of atherosclerosis

Answer 7

fatty streak - macrophages enter lesion and become foam cells
further accumulation of lipids thickens the intimacy
plaque impinges the vessel lumen

Question 8

describe the consequences of atherosclerosis

Answer 8

rupture of the plaque exposing intimal surface

induces thrombosis and lumen occlusion which leads to ischeamia, atherothrombelism and aneurysm formation

Question 9

what is a thrombus

Answer 9

solid mass of blood constituents within an intact vessel which is veinous and arterial

Question 10

what is a haemostatic plug

Answer 10

forms at site of vascular injury and is not pathological

Question 11

what is the mechanism, location, associated diseases, composition and treatment of arterial thrombosis

Answer 11

mech - forms from rupture of atheromatous plaque

loc - left heart chambers, arteries

dis - acute coronary syndrome, ischemic stroke

comp - mainly platelets

treatment - anti-platelet agents (clopidogrel)

Question 12

what is the mechanism, location, associated diseases, composition and treatment of venous thrombosis

Answer 12

mech - combination factors from virchows triad

loc - venous sinusoids of muscles and valves of veins

dis - DVT and pul embolism

comp - mainly fibrin

treat - anticoagulants (heparin and warfarin)

Question 13

how do we naturally inhibit thrombosis

Answer 13

natural anticoagulants such as protein C (proteolysis of Va and VIIIa, need protein s)

Question 14

what factors favour thrombosis formation

Answer 14

platelet aggregation, adhesion and clotting factors

Question 15

a venous thrombosis is determined by what

give examples

Answer 15

virchows triad

• endothelial injury
• hyper coagulability
• abnormal blood flow

immobility and lack of muscle contraction = stasis of blood

polycythaemia - viscous blood and hypercoaguable

Question 16

describe the consequences of thrombosis

Answer 16

occlusion of vessel - ischaemia 
dissolution 
incorporation into vessel wall 
recanalisation 
embolisation

Question 17

what is an embolism

Answer 17

a mass of material in the vascular system which can be lodged in a vessel and block the lumen

Question 18

what are the most common types of embolus and other types

Answer 18

pulmonary embolus derived from DVT

embolus can be:
thrombus derived
atheromatous plaque 
infective endocarditis 
tumour fragments 
amniotic fluid 
gas 
fat