Flashcards in Pathology - Atherosclerosis Deck (29):
1
What is atherosclerosis?
The accumulation of intracellular and extracellular lipid in the intima and media of large/medium arteries leading to thickening and hardening of arterial walls
2
What is arteriosclerosis?
The thickening of the walls of arteries and arterioles, usually as a result of hypertension or diabetes mellitus
3
What is the same given to a yellow, slightly raised lipid deposit in the lumen of an artery?
Fatty streak
4
How does a simple plaque appear in the lumen?
Raised yellow/white, irregular outline, widely distributed, can enlarge and coalesce
5
Why is a complicated plaque more dangerous than a simple plaque?
- can lead to thrombosis
- can lead to haemorrhage into plaque
- can lead to calcification of arteries
- may cause aneurysm formation
6
Give some common sites of atherosclerosis
Aorta (especially abdominal), coronary arteries, carotid arteries, cerebral arteries, leg arteries
7
What are the EALRY microscopic features of atherosclerosis?
Proliferation of smooth muscle cells, accumulation of foam cells, extracellular lipid
8
What are the ADVANCED microscopic features of atherosclerosis?
Fibrosis, necrosis, cholesterol clefts, inflammatory cells, disruption of internal elastic lamina, damage extends into media, ingrowth of blood vessels, plaque fissuring
9
Give some clinical effects of atherosclerosis which relate to ischaemic heart disease
Ischaemic heart disease:
- sudden death
- myocardial infarction
- angina pectoris
- arrhyhmias
- cardiac failure
10
Give some clinical effects of atherosclerosis which relate to cerebral ischaemia
- transient ischaemic attack
- cerebral infarction
- multi-infarct dementia
11
Give some effects of atherosclerosis which relate to mesenteric ischaemia
Ischaemic colitis, malabsorption, intestinal infarction
12
Give some clinical effects of atherosclerosis which relate to peripheral vascular disease
- intermittent claudication
- Leriche syndrome
- ischaemic rest pain
- gangrene
13
Give some pre-disposing factors for atherosclerosis
- age (risk increases as get older)
- gender (women protected before menopause)
- hyperlipidaemia (high plasma cholesterol associated with atherosclerosis)
- cigarette smoking
- hypertension (possibly due to endothelial damage caused by raised pressure)
- diabetes mellitus
- alcohol
- infection (chlamydia pneumoniae, H. Pylori, cytomegalovirus)
- lack of exercise/obesity
- soft water
- oral contraceptives
- stress (uncertain)
14
How is atherosclerosis associated with apolipoprotein E?
- genetic variations in Apo E are associated with changes in LDL levels
- polymorphisms of these genes can be used as risk markers for atherosclerosis
15
Give some physical signs of familial hyperlipidaemia
- corneal arcus
- tendon xanthomas
- xanthelasma
16
What was the thrombogenic theory of atherosclerosis?
Plaques formed by repeated thrombi, lipid is derived from these. Overlying fibrous cap forms
17
What was the insulation theory of atherosclerosis?
Endothelial injury leads to inflammation and increased permeability to lipid from plasma
18
What is the reaction to injury hypothesis of atherosclerosis?
- plaques form in response to endothelial injury
- injury increases permeability and allows platelet adhesion
- monocytes penetrate endothelium
- smooth muscle cells proliferate there and migrate
19
What is the monoclonal hypothesis of plaque formation?
Each plaque is monoclonal, so they may represent abnormal growth control - could be a benign tumour
20
Which cell types are involved in atherosclerosis?
- endothelial cells
- platelets
- smooth muscle cells
- macrophages
- lymphocytes
- neutrophils
21
What is the role of endothelial cells in atherosclerosis?
- altered permeability to lipoproteins
- production of collagen
- stimulation of proliferation/migration of smooth muscle cells
22
What is the role of platelets in atherosclerosis?
Stimulate proliferation and migration of smooth muscle cells
23
What is the role of smooth muscle cells in atherosclerosis?
Take up LDL and other lipids to become foam cells, synthesise collagen and proteoglycans
24
What are the roles of macrophages in atherosclerosis?
- oxidise LDL
- take up lipids to become foam cells
- secrete proteases which modify the matrix
- stimulate proliferation and migration of smooth muscle cells
25
What are the roles of lymphocytes in atherosclerosis?
- stimulate proliferation and migration of smooth muscle cells
- TNF may affect lipoprotein metabolism
26
What is the role of neutrophils in atherosclerosis?
Secrete proteases leading to continued local damage and inflammation
27
What methods can be used to help prevent atherosclerosis?
- no smoking
- reduce fat intake
- treat hypertension
- not too much alcohol
- regular exercise/weight control
28
What interventions can be used to help prevent a high risk individual from developing atherosclerosis?
- stop smoking
- modify diet
- treat hypertension
- treat diabetes
- lipid lowering drugs
29