Atherosclerosis

Question 1

Histological Layers of Vessels

Answer 1

Tunica Intima - Endothelium, SEL, IEM
Tunica Media - Smooth Muscle, EEM
Tunica Externa - vasa vasorum

Question 2

Pathophysiology of Atherosclerosis

Answer 2

Endothelial Injury - from hypertension, hyperlipid, toxin, virus
- triggers inflammation, leading to WBC emigration, increased endothelial permeability, macrophage activation

• LDL invades endothelium, becomes Oxidised, recruits macrophages
• macrophages engulf OxLDL - Foam Cells - Fatty Streaks
• macrophages die, trigger more WBC, lipid accumulation, calcification;
• Fibrous cap under endothelium involving macrophages, foam cells, lymphocytes, SM cells
• Atheroma of Fibrous cap and Lipid debris (core)
• smooth muscle recruited to intima layer

Question 3

Risk Factors

- modifiable and non-m

Answer 3

Modifiable
- Hyperlipid, Hypertension, Smoking, Diabetes

Non-m
Age, Male, Family history

Question 4

Structural changes by atherosclerosis and their consequences

Answer 4

Lumen narrowing - Ischemia
Loss of elasticity - Aneurysm - Rupture, haemorrage
Endothelial changes - thrombosis

Question 5

Virchow’s Triad

Answer 5

Hypercoagulability
Endothelial Damage
Stasis