Flashcards in MOD S7 - Atheroma Deck (19)
The accumulation of intracellular and extracellular lipid in the tunica intima and tunica media of large and medium sized arteries
The thickening and hardening of arterial walls as a result of atheroma
The thickening and hardening of arterial and arteriolar walls, usually as a result of diabetes mellitus or hypertension
Describe the macroscopic appearance of an early atheroma
Lipid deposits in the tunica intima
Yellow and slightly raised
Describe the macroscopic appearance of a developing atheroma
Enlarged and coalesced
Describe the microscopic appearance of a developing atheroma
Proliferation of smooth muscle cells
Accumulation of foam cells
Describe the microscopic appearance of a late-stage atheroma
Cholesterol deposition in tissues (not plaque)
Describe the macroscopic appearance of a late-stage atheroma
Haemorrhage into plaque
Describe the cellular events that take place in atheroma formation
Endothelial damage occurs
PDGF released (platelet derived growth factor)
Smooth muscle cells proliferate
Smooth muscle cells migrate and take lipid with them
Macrophages arrive and phagocytose the lipid, becoming foam cells
What could some effects of atherosclerosis be if it was in a coronary artery?
Ischaemic heart disease
What could some effects of atherosclerosis be if it was in the brain?
Transient ischaemic attack (symptoms for <24h)
Cerebral infarction (aka stroke)
Multi infarct dementia
What could some effects of atherosclerosis be if it was in a mesenteric artery?
Aneurism formation due to high pressure, hardening and weakening
What could some effects of atherosclerosis be if it was in a peripheral artery?
Peripheral vascular disease
Ischaemic rest pain
What is intermittent claudication?
Pain on exertion of calf muscles
Due to blockage or narrowing of peripheral arteries causing pain and ischaemia
NB intermittent claudication in the iliac artery causes gluteal pain
What are some risk factors for atheroma?
Lack of exercise
Why is gender a risk factor for atheroma?
Pre-menopausal women have some measure of resistance to atheroma
Thought to be hormone related
NB slightly conflicts with oral contraceptives
Briefly describe the unifying hypothesis of atherogenesis
Endothelial injury occurs
Platelets adhere to vessel walls
Smooth muscle cell proliferation and migration
Insudation of lipid
Uptake of lipid by SMCs and macrophages
Migration of monocytes into tunica intima
Foam cells secrete cytokines
Cytokines further stimulate SMCs and recruit immune cells
How may atheromas be prevented?
Change diet (less fat)
Change lifestyle (more exercise)