Atheroma

Question 0

Definition of atheroma

Answer 0

Patchy accumulation of fat within the walls of an artery

Question 1

Term synonymous with atheroma

Answer 1

Atherosclerosis

Question 2

Best understood pathogenesis of atheroma

Answer 2

Response to injury hypothesis

Question 3

Describe response to injury hypothesis

Answer 3

1. Endothelial cells injured
2. Monocytes and platelets adhere to injury site
3. Monocytes enter intimate where they differentiate into macrophages, platelets release growth factor
4. Damage increases lipoprotein permeability so LDL enters intima

Question 4

First stage of atheroma after pathogenesis

Answer 4

Formation of fatty streak within intima

Question 5

Second stage of atheroma

Answer 5

Fat ingested by macrophages forming ‘foamy macrophages’

Question 6

Third stage of atheroma

Answer 6

Foam cells die releasing lipid into extracellular space, which prompts chronic inflammatory response recruiting T cells and more macrophages

Question 7

Fourth stage of atheroma

Answer 7

Smooth muscle cells multiply and migrate into intima where they become fibroblast-like and secret collagen

Question 8

Fifth stage of atheroma

Answer 8

Lesion enlarges with central lipid part becoming necrotic

Question 9

Composition of a mature plaque

Answer 9

• Fibrous cap containing smooth muscle cells and collagen
• Necrotic lipid-rich core
• Chronic inflammation with T cells, macrophages and smooth muscle cells

Question 10

What part of the plaque is the ‘shoulder’

Answer 10

Sides of the plaque where blood vessel proliferation is most marked, site most likely to haemorrhage

Question 11

Complications of atheroma

Answer 11

• Narrowing of arteries
• Haemorrhage into plaque
• Thrombosis causing complete occlusion
• Embolism of necrotic core material
• Aneurysm formation

Question 12

How can atheroma lead to aneurysm formation?

Answer 12

Plaque erodes tunica media weakening the artery wall