Atheroma Vascular Disease Flashcards Preview

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Flashcards in Atheroma Vascular Disease Deck (30)
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1
Q

What is arteriosclerosis?

A

Thickening and hardening of wall of an artery

2
Q

Arteriolosclrosis

A

Thickening and hardening of the wall of an arteriole

3
Q

Atheroma

A

Important disease of large and medium arteries

Initially disease of tunica intima, later affects tunica media

4
Q

Atherosclerosis

A

Arteriosclerosis due to atheroma

5
Q

What is the most common cause of thickening and hardening of the Walls in large and medium arteries

A

Atheroma

6
Q

What is the most common cause of thickening and hardening of the walls of small arteries and arteriolar

A

High blood pressure

7
Q

Changes in small arteries due to hypertensive arteriosclerosis

A

Hypertrophy of media
Fibroelastic thickening of intima
Elastic lamina reduplication

8
Q

Changes in arterioles due to hypertensive arteriosclerosis

A

Replacement of wall structures by amorphous hyaline material

9
Q

Consequences of hypertensive vascular changes

A

Reduction of vessel lumen - reduced flow - ischaemia in supplied tissue
Increased rigidity of vessel wall - loss of elasticity and contractility - unresponsive to normal vessel control agents eg. vasodilators

10
Q

Do atheromas occur in high or low pressure systems?

A

High

Systemic arterial system, not venous

11
Q

Characteristic of atheroma

A

Ubiquitous
Very mild in young people
Worsening with age

12
Q

Visually, how does atheroma develop?

A

Fatty streak
Lipid plaque
Fibrolipid plaque
Complicated atheroma

13
Q

Stages of atheroma development?

A

LDL enter through damaged endothelium
Lipids are phagocytosed by macrophages in intima to make raised fatty streak - accumulation of the macrophages
Some lipid is released by macrophages - lipid plaque
Macrophages secrete cytokines which stimulate myofibroblasts to secrete collagen
Early damage of elastic lamina and media
Collagen covers plaque surface - fibrolipid plaque
Media thins with replacement of muscle fibres by collagen
Lipids in intima become calcified
Surface of fibrolipid plaque ulcerates
Thinning of media leads to weakness and inelasticity - complicated atheroma

14
Q

What will eventually occur to the lipids?

A

Degenerate and calcium deposited
Calcified
Increase rigidity of blood vessel

15
Q

Risk factors of atherosclerosis

A

Smoking
Fast food
High BMI
Low activity

16
Q

Complications of atheroma

A

Expansion of intima -> reduction of size of lumen -> reduced blood flow & hence oxygenation of tissue
Ulceration of atheromatous intima -> predisposition to thrombus formation -> vessel occlusion
Plaque fissure formation & haemorrhage
Replacement of muscle & elastic fibres in media -> loss of elasticity -> thinning and stretching (ANEURYSM)

17
Q

What will reduction of lumen lead to?

A

Reduced blood flow, reduced oxygenation of tissues, therefore Ischaemic damage to tissues

18
Q

Atheroma in coronary arteries

A

Angina - chest pain

19
Q

Atheroma in leg arteries

A

Intermittent claudication

20
Q

Atheroma in mesenteric arteries

A

Ischaemic colitis - can cause extensive bleeding of bowel

Or haemorrhage

21
Q

Atheroma in cerebral and vertebral arteries

A

Cerebral ischaemic events (stroke)

22
Q

What may occur is reduction in flow is severe enough?

A

Tissue may die due to hypoxia - infarction

23
Q

How can an atheroma cause thrombosis

A

Damaged and ulcerated endothelium may lead to formation of thrombus
May complete occlusion of vessel lumen

24
Q

How can an atheroma cause plaque fissures

A

Blood sleeps into atheromatous plaque and expands it

Or blood seeps into plaque and undergoes thrombosis

25
Q

What is an aneurysm

A

Abnormal permanent focal dilatation of an artery

26
Q

Types of aneurysm

A

Syophilitic
Development in cerebral vessels
Dissecting aneurysms of thoracic aorta
Mycotic aneurysms

27
Q

Main types of aneurysms

A

Saccular
Fusiform
Dissecting

28
Q

How can damage to media lead to aneurysm?

A

Enlarging intimal atheroma plaque leads to atrophy of media
Muscle and elastic fibres in media replaced by collagen
Collagen strong but neither contractile or can do elastic recoil, therefore:
Each systolic pulse, wall of artery stretches and thins

29
Q

Common aneurysms

A

Atheromatous aortic
Aortic dissecting
Cerebral ‘berry’

30
Q

Cause of uncommon mycotic aneurysm

A
Endocarditis (infection of heart valve)
Bacterial septicaemia
Infection of arterial wall
Weakening and dilatation 
Risk of bleed