Session 6 Flashcards
(26 cards)
What is the definition of atherosclerosis?
Atherosclerosis is the accumultion of intracellular and extracellular lipid in the intima and media of large and medium sized arteries.
What is the definition of atheroma?
The thickening ans hardening of arterial walls as a consequence of atherosclerosis.
What is the definition or arteriosclerosis?
The thickening of the walls of arteries and aretioles usually as a result of hypertension or diabetes mellitus.
What are macroscopic features of atherosclerosis?
fatty sreak, simple plaque, complicated plaque
What is a fatty streak?
It is a macroscopic rfeature of atherosclerosis caracterised by
- lipid deposits in intima
- yellow, slightly raised
- relationship to atherosclerosis somewhat debatable. (they are seen worldwide even in populations without atherosclerosis)
What is a simple plaque?
It is a macroscopic feature of atherosclerosis. caracterised by: - raised yellow/white - irrugular outline - widely distributed - will enlarge and coalesce
What is a complicated plaque?
It is a macroscopic feature of atherosclerosis.
- thrombosis
- haemorrhage into plaque
- calcification
- aneurysm formation
=> at this point, something extra happens, like haemorrhage into the plaque. Indeed, small new blood vessels have formed in the plaque and ruptured so are now bleeding.
Which vessels are common sites for atherosclerosis?
- aorta, especially abdominal
- coronary arteries
- carotid arteries
- cerebral arteries
- leg arteries
NOT arms!
At which level in the abdominal aorta is atherosclerosis particularly common?
Between the renal arteries and aortic bifurcation (into common iliac arteries)
Which microscopic features appear early on in atherosclerosis?
- proloferation of smooth muscle cells
- accumulation of foam cells (ie. lipid inside cells)
- extracellular lipid
Which microscopic features appear later in atherosclerosis?
- fibrosis (fibroblast proliferation)
- necrosis
- cholesterol clefts (extracellular lipid in form of cholesterol will be present in the shape of needles, and will then. be digested, leeving clefts)
- +/- inflammatory cells (varies from individual to individual)
- disruption of internal elastic lamina
- damage extends into media
- ingrowth of blood vessels
- plaque fissuring - exposes substances that will lead to thrombosis
What are the clinical effects of artherosclerosis?
- Ischaemic heart disease
- Sudden death
- Myocardial infarction
- Angina pectoris (chest pain on exertion)
- Arrythmias
- Cardiac failure - Cerebral ischaemia
- TIA
- cerebral infarction (stroke)
- multi-infarct dementia - Mesenteric ischaemia
- ischaemic colitis (++ splenic flexture)
- malabsorption
- intestinal infarction - Peripheral vascular disease
- intermittent claudication
- Leriche syndrome (buttock pain instead of calves and associated with incontinence)
- ischaemic rest pain
- gangrene
What macroscopically shows fresh MI?
Red border around the yellowish material
What are some risk factirs controbuting to atherosclerosis?
- age
- gender - women protected before menopause
- hyperlipidaemia
- cigarette smoking
- hypertension
- diabetes mellitus
- alcohol
- infection
What are familial hyperlipidaemias?
Genetically determined abnormalities of lipoproteins. They lead to early development of atherosclerosis.
What are the associated physical signs of familial hyperlipidaemias? (3)
- Arcus
- Tendon xanthomas
- Xanthelasma
What are xanthelasmas?
They are shaply demrked yellowish deposit of fat underneath the skin, usually on or around the eyelids.
They are cutaneous manifestations of lipidosis in which lipids accumulate in LARGE FOAM CELLS within the skin.
They are associated with hyperlipidaemias.
What is corneal arcus?
Arcus is a deposition of lipid in the peripheral corneal stroma. It appears macroscopically as a white, grey, blue opaque ring in the corneal margin.
Can be indicative of a hyperlipoprotinaemia with elevated serum cholesterol, especially in patients under 40 years of age.
Which infections are potentially implicated in atherogenesis?
- chlamydia pneumoniae
- helicobacter pylori
- cytomegalovirus
Which are the 4 theories on how atheromatous plaques are generated?
- Thrombogenic thepry
- Insudation theory
- Monoclonal hypothesis
- Reaction to injury hypothesis
Which cell types are involved in atherogenesis?
- endithelial cells
- platelets
- smooth muscle cells
- macrophages
- lymphocytes
- neutrophils
Which cell types involved in atherosclerosis simulate proliferation and migration of smooth muscle cells?
- platelets
- macrophages
- lymphocytes
- endothelial cells
Which cells types involved in atherosclerosis do not stimulate smooth muscle cell proliferation and migration?
Neitrophils
From which cell type do foam cells develop?
Macrophages
They take up lipids and get this foamy appearance.
