Session 6

Question 1

What is the definition of atherosclerosis?

Answer 1

Atherosclerosis is the accumultion of intracellular and extracellular lipid in the intima and media of large and medium sized arteries.

Question 2

What is the definition of atheroma?

Answer 2

The thickening ans hardening of arterial walls as a consequence of atherosclerosis.

Question 3

What is the definition or arteriosclerosis?

Answer 3

The thickening of the walls of arteries and aretioles usually as a result of hypertension or diabetes mellitus.

Question 4

What are macroscopic features of atherosclerosis?

Answer 4

fatty sreak, simple plaque, complicated plaque

Question 5

What is a fatty streak?

Answer 5

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)

Question 6

What is a simple plaque?

Answer 6

It is a macroscopic feature of atherosclerosis.
 caracterised by:
- raised yellow/white
- irrugular outline
- widely distributed
- will enlarge and coalesce

Question 7

What is a complicated plaque?

Answer 7

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.

Question 8

Which vessels are common sites for atherosclerosis?

Answer 8

• aorta, especially abdominal
• coronary arteries
• carotid arteries
• cerebral arteries
• leg arteries

NOT arms!

Question 9

At which level in the abdominal aorta is atherosclerosis particularly common?

Answer 9

Between the renal arteries and aortic bifurcation (into common iliac arteries)

Question 10

Which microscopic features appear early on in atherosclerosis?

Answer 10

• proloferation of smooth muscle cells
• accumulation of foam cells (ie. lipid inside cells)
• extracellular lipid

Question 11

Which microscopic features appear later in atherosclerosis?

Answer 11

• 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

Question 12

What are the clinical effects of artherosclerosis?

Answer 12

1. Ischaemic heart disease
   - Sudden death
   - Myocardial infarction
   - Angina pectoris (chest pain on exertion)
   - Arrythmias
   - Cardiac failure
2. Cerebral ischaemia
   - TIA
   - cerebral infarction (stroke)
   - multi-infarct dementia
3. Mesenteric ischaemia
   - ischaemic colitis (++ splenic flexture)
   - malabsorption
   - intestinal infarction
4. Peripheral vascular disease
   - intermittent claudication
   - Leriche syndrome (buttock pain instead of calves and associated with incontinence)
   - ischaemic rest pain
   - gangrene

Question 13

What macroscopically shows fresh MI?

Answer 13

Red border around the yellowish material

Question 14

What are some risk factirs controbuting to atherosclerosis?

Answer 14

• age
• gender - women protected before menopause
• hyperlipidaemia
• cigarette smoking
• hypertension
• diabetes mellitus
• alcohol
• infection

Question 15

What are familial hyperlipidaemias?

Answer 15

Genetically determined abnormalities of lipoproteins. They lead to early development of atherosclerosis.

Question 16

What are the associated physical signs of familial hyperlipidaemias? (3)

Answer 16

1. Arcus
2. Tendon xanthomas
3. Xanthelasma

Question 17

What are xanthelasmas?

Answer 17

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.

Question 18

What is corneal arcus?

Answer 18

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.

Question 19

Which infections are potentially implicated in atherogenesis?

Answer 19

• chlamydia pneumoniae
• helicobacter pylori
• cytomegalovirus

Question 20

Which are the 4 theories on how atheromatous plaques are generated?

Answer 20

1. Thrombogenic thepry
2. Insudation theory
3. Monoclonal hypothesis
4. Reaction to injury hypothesis

Question 21

Which cell types are involved in atherogenesis?

Answer 21

• endithelial cells
• platelets
• smooth muscle cells
• macrophages
• lymphocytes
• neutrophils

Question 22

Which cell types involved in atherosclerosis simulate proliferation and migration of smooth muscle cells?

Answer 22

• platelets
• macrophages
• lymphocytes
• endothelial cells

Question 23

Which cells types involved in atherosclerosis do not stimulate smooth muscle cell proliferation and migration?

Answer 23

Neitrophils

Question 24

From which cell type do foam cells develop?

Answer 24

Macrophages

They take up lipids and get this foamy appearance.

Question 25

What are preventives measures for atherosclerosis?

Answer 25

• no smoking
• reduce fat intake
• treat hypertension
• not too much alcohol
• regular exercise/weight control

Question 26

What are interventive measures for atherosclerosis?

Answer 26

• stop smoking
• modify diet
• treat hypertension
• treat diabetes
• lipid lowering drugs