MoD - Atheromas

Question 0

What is atherosclerosis?

Answer 0

The thickening and hardening of arterial wall (as a consequence of atheromas forming containing cholesterol and lipid)

Question 1

What is the definition of atheroma?

Answer 1

The accumulation of intracellular and Extracellular lipid in the intima and media of large and medium arteries (plaque)

Question 2

What is arteriosclerosis?

Answer 2

Hardening of arterioles and arteries as a result of hypertension or diabetes

Question 3

Where does atherosclerosis tend to develop in the artery?

Answer 3

In patches of the intima often where flow is disturbed.

Question 4

What is the first step in atheroma formation?

Answer 4

Transendothelial passage of lipid droplets (which become oxidised) and macrophages that engulf the lipid and become foam cells

Question 5

What is the second step in atheroma formation?

Answer 5

Crowded foam cells cause endothelium to bulge. Smooth muscle cells arise from the media (fatty streak)

Question 6

What is the third step in atheroma formation?

Answer 6

Growth of the plaque by increased no of foam cells and SM

Platelets adhere where gaps in the endothelium form. ‘Roof’ forms from coallgen, elastic and other matrix - fibrous cap!

Question 7

What is the fourth step in atheroma formation?

Answer 7

Necrosis occurs in the plaque followed by development of cholesterol crystals, calcification and vascularisation

Question 8

What are some complications of plaque development?

Answer 8

Ulceration - fibrous cap is eroded from underneath and the core is exposed
Thrombosis may develop
Thrombi can release vasoconstrictors which cause spasm at the site of plaque
Haemorrhage may occur if one of the developing vessels bursts
Aneurysm may be caused from a weakening of the wall

Question 9

What is an aneurysm?

Answer 9

Local dilatations of an artery due to weakening of the arterial wall

Question 10

What is the first cellular event leading to the formation of atherosclerosis?

Answer 10

Chronic endothelial injury ( e.g hyperlipidaemia, hypertension, smoking)

Question 11

What is the second cellular event leading to the formation of atherosclerosis?

Answer 11

Monocyte and platelet adhesion releasing cytokines which cause migration of smooth muscle

Question 12

What is the third cellular event leading to the formation of atherosclerosis?

Answer 12

Smooth muscle emigration p, macrophage activation

Question 13

What is the fourths cellular event leading to the formation of atherosclerosis?

Answer 13

Macrophages and smooth muscle, cells engulf lipid and oxidase LDLs forming foam cells

Question 14

What is the fifth cellular event leading to the formation of atherosclerosis?

Answer 14

Smooth muscle proliferation - collagen and other ECM deposition, Extracellular lipid

Question 15

What is the morphological appearance of a fatty streak? Q

Answer 15

Flat( or slightly raised), lipid filled foam cells, yellow

Question 16

What is the morphological appearance of the atherosclerotic plaques?

Answer 16

Raised yellow/white, irregular outline, widely distributed

Complicated plaque = haemorrhage, calcification

Question 17

What are the 2 dyslipidaemias that promote atherosclerosis?

Answer 17

Increased LDL

Decreased HDL

Question 18

What are the 6 cell types involved in atheromas?

Answer 18

Endothelial cells
Platelets 
Smooth muscle
Macrophages
Lymphocytes
Neutrophils

Question 19

What are the risk factors associated with atheromas?

Answer 19

Set - Age, sex, genetics,

Modifiable - smoking, hypertension, hyperlipidaemia, diabetes

Question 20

What is the main prevention for atheroma?

Answer 20

Decrease total LDL through diet and lipid lowering drugs