Vascular disease: atheroma

Question 1

atheroma

Answer 1

disease of large and medium arteries
only occurs in high pressure system (arteries not veins)
initially occurs in tunica intima then tunica media
ubiquitous- mild in young age then worsens with age

Question 2

arteriosclerosis

Answer 2

thickening and hardening of wall of arteries

Question 3

arteriolosclerosis

Answer 3

thickening and hardening of walls of arterioles

Question 4

the most common cause of arteriosclerosis in large and medium arteries

Answer 4

atheroma

Question 5

the most common cause of thickening and hardening in small arteries and arterioles

Answer 5

high bp

Question 6

hypertensive arteriosclerosis

Answer 6

1. hypertrophy of media
2. fibroelastic thickening of intima
3. elastic lamin reduplication

Question 7

hypertensive arteriolosclerosis

Answer 7

wall structure replaced by amorphous hyaline material

Question 8

consequences of hypertensive vascular changes

Answer 8

1. reduced vessel lumen-> reduced blood flow-> ischaemia

2. rigidity and vessel wall-> decreased elasticity and contractility-> unresponsive to control agents (vasodilation)

Question 9

how does an atheroma develop?

Answer 9

recognisable stages with naked eye:

1. fatty streaks
2. lipid plaque
3. fibrolipid plaque
4. complicated atheroma

Question 10

details of atheroma development

Answer 10

1. lipid enters intima through damaged endothelium
2. macrophage phagocytose lipids to make fatty streak
3. some lipids released by macrophage creating lipid plaque
   macrophage release cytokines- myofibroblast secrete collagen
   early damage to elastic lamina and media
4. collagen covers plaque surface- fibrolipid plaque
5. media thins- muscle replaced by collagen
6. lipids in intima become calcified
   surface of fibro lipid plaque ulcerates
   thinning of media- weakness and inelasticity- complicated atheroma

Question 11

risk factors of atheroma

Answer 11

smoking, obesity, sedentary lifestyle, fatty diet

Question 12

complications of atheroma

Answer 12

1. expansion of intima, reduced lumen size, ischaemia (can also lead to infarction as tissue dies from hypoxia)
2. ulceration of atheromatous intima- predisposition to thrombus- vessel occlusion
3. plaque fissure formation and haemorrhage
4. replacement of muscle and elastic stretching of media- loss of elasticity- thinning and stretching- aneurysm

Question 13

how can damage to media lead to an aneurysm

Answer 13

enlarging intimal atheroma leads to atrophy of media
muscle and elastic fibres replaced by collagen
collagen strong but cannot contract or elastic recoil
with each systolic pulse artery wall stretches and things esp with high bp

Question 14

aneurysm

Answer 14

abnormal permanent focal dilation of an artery

most common in abdominal, cerebral berry and dissecting aortic