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Flashcards in Vascular pathology Deck (72)
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1
Q

What is an atheroma?

A

Condition characterised by focal accumulation of lipid in the intima of arteries (inner most layer)

2
Q

What is atherosclerosis?

A

Atheroma causing hardening of arteries

3
Q

List 7 risk factors of atherosclerosis?

A

Increasing age
Male
Smoking - carbon monoxide damages endothelial cells lining the arteries
Hypertension - blood cells don’t normally contact the endothelium, in hypertension = turbulence - blood cells contact endothelium
Diabetes mellitus
Raised LDL - cholesterol blood levels
Family history

4
Q

List 3 pre-disposing factors of atherosclerosis?

A

Obesity
Lack of exercise
Low socio-economic status

5
Q

List the stages of an atherosclerosis lesion

A

Fatty streak
Fibrolipid plaque
Complicated lesion

6
Q

How do veins and arteries differ histologically?

A

Arteries are smaller and have much thicker walls

7
Q

Describe the wall of an artery?

A

Inner = internal elastic lamina
Tunica Media
External elastic lamina
Outer = Tunica adventitia

8
Q

Name 2 types of arteries?

A

Elastic and muscular

9
Q

In a muscular artery what is the tunica media made of?

A

Smooth muscle cells

10
Q

In an elastic artery where is elastic material found?

A

Between inner and outer elastic lamina

11
Q

What is the first stage in the formation of an atherosclerosis lesion?

A

Fatty streak

12
Q

What is the first event occurring during the formation of a fatty streak? What is the effect of this?

A

Endothelial image leading to permeability, monocyte adhesion to the endothelium so monocytes and LDL can enter the artery

13
Q

What is the major characteristic of a fatty streak?

A

Foamy macrophages - Monocytes that have entered and injected LDLs. They cannot digest the fat so they sit in the intima

14
Q

Through what process do monocytes enter the intima?

A

Diapedesis

15
Q

What triggers monocytes to invest LDLs?

A

Cytokines released form T cells within the fatty streak cause maturation into macrophages, these ingest the LDLs and form foam cells

16
Q

How can a fatty streak develop into a fibrolipid plaque?

A

T cells release cytokines that cause the release of smooth muscle cells from the tunica media into the intima. These ingest LDLs

17
Q

How does the artery change when a fatty streak develops into a fibrolipid plaque?

A

The plaque becomes more prominent and elevated

18
Q

How does the artery change when a fatty streak develops into a fibrolipid plaque?

A

The plaque becomes more prominent and elevated

19
Q

Fibrolipid plaques bulge into what structure?

A

Lumen of artery

20
Q

Describe what occurs in the fibrolipid plaque?

A

Smooth muscle cells migrate to the surface of the intima, these are followed by fibroblasts .
Proliferation occurs, there is more lipid uptake and collagen is produced

21
Q

What cells are seen in a fibrolipid plaque?

A

Foamy macrophages, Smooth muscle cells, lymphocytes and fibroblasts

22
Q

How does a lipid lake form in a fibrolipid plaque?

A

Foamy macrophages breakdown and form a lipid lake

23
Q

In the fibrolipid plaque stage, is the endothelium intact?

A

Yes but it is bulging into the lumen - this gives the opportunity for blood cells and platelets to impact on the surface of the fibrolipid plaque

24
Q

What follows the impaction of platelets onto the surface fo the fibrolipid plaque?

A

Formation of complicated lesion

25
Q

What is the consequence of a complicated lesion forming?

A

Leads to thrombosis

26
Q

Describe how a complicated lesion forms?

A

Occlusion of platelets on the surface of the fibrolipid plaque and endothelium layer is lost. Causes the clotting cascade to begin. This forms a thrombus on the plaque.

27
Q

What 5 things occur after the formation of a complicated lesion? Why?

A
Haemorrhage into plaques
Plaque fissuring and rupture
Embolism
Calcification
Aneurysm formation 
Because complicated lesions can occlude the whole artery
28
Q

Where does atherosclerosis occur in the arteries?

A

Bifurcations of arteries

more possibility for platelets to impact

29
Q

Which artery are clinical effects most prominent?

A

Coronary arteries

30
Q

List some consequences of atherosclerosis?

A

Ischaemic heart disease
Aortic aneurysm
Small bowel ischaemia and infarction
Peripheral vascular disease

31
Q

What is angina pectorals?

A

Pain in the left side down the arm during exercise

32
Q

What is myocardial infarction?

A

Heart muscle dies as a result of ischaemia

33
Q

What is intermittent claudication? What causes it?

A

Pain in legs during exercise due to peripheral vascular disease

34
Q

Name 3 ways atherosclerosis can be managed?

A

Lifestyle
Medical
Surgical

35
Q

How can lifestyle be used to manage atherosclerosis?

A

Healthy eating, exercise and not-smoking

36
Q

Name 3 drugs used to manage atherosclerosis?

A

Cholesterol medications, anti-platelet medications, beta blocker medication

37
Q

Name 4 surgical process used to manage atherosclerosis?

A

Angioplasty
Stent
Bypass
Endarterectomy

38
Q

What is a thrombus?

A

Solid mass of blood constitutents formed within the vascular system during life

39
Q

How do thrombus and clot differ?

A

Clot forms outside vascular system

40
Q

What is an embolism?

A

Passive transport of a substance within the vascular system

41
Q

What is ischaemia?

A

Inappropriate reduction in blood supply to an organ or tissue

42
Q

What is infarction?

A

Death of tissue due to ischaemia

43
Q

What is an aneurysm?

A

Localised permanent abnormal dilation of a blood vessel due to weakening of the blood vessel wall

44
Q

What 3 things are known to result in thrombosis?

A

Changes in the intimal surface of vessel
Changes in the pattern of blood flow
Changes in the blood constituents

45
Q

What are Virchows Triad?

A

Changes in the intimal surface of vessel
Changes in the pattern of blood flow
Changes in the blood constituents

3 factors that result in thrombosis

46
Q

What is a good example of changes to the intimal surface that will result in thrombosis?

A

Atherosclerosis - intimal surface ulcerated

47
Q

What is a good example of changes in pattern of blood flow that will result in thrombosis?

A

Venostasis
Blood is stagnant, platelets drop out and clot
Injury or compression where the turbulence results in adherence of platelets to endothelium = thrombus

48
Q

What is a good example of changes in the blood constituents that will result in thrombosis?

A

Anything that makes the blood hyper-coagulable

49
Q

Why do atheromas lead to thrombosis?

A

Platelets land on top of the atheroma and aggregate and release clotting factors and fibrin forms trapping RBC = more aggregation, causing propagation of the thrombus

50
Q

How do Venus thrombus occurs?

A

Due to stasis often around valves

51
Q

In what patients often does Venus thrombus occur?

A

Burns and trauma, after surgery, cardiac failure, pregnancy, immobility, long haul lights

52
Q

What is thrombophlebitis?

A

Inflammation of the deep vein

53
Q

What is phlebothrombosis?

A

Stagnation of the deep vein so platelets drop out of circulation and form a thrombus

54
Q

Where in the heart can cardiac thrombosis occur?

A

Atria or valves

55
Q

In the atrium, conditions like atrial fibrillation and mitral stenosis occurs, how can this cause thrombosis?

A

Change in blood flow - platelets contact normal endothelium due to turbulence

56
Q

In the valves, thrombosis can occur due to rheumatic fever and endocarditis, why is this?

A

Due to vegetations, thrombosis occurs on top of these

57
Q

How can thrombosis occur in the ventricle?

A

If myocardial infarction occurs and the heart wall dies and thrombus can occur here

58
Q

4 fates of thrombi?

A

Lysis and resolution
Retraction and re-canalisation
organisation and scarring
embolism

59
Q

What is the best outcome of thrombi?

A

Lysis and resolution

60
Q

Describe lysis and resolution of thrombi?

A

Complete dissolution of thrombus and complete return to normal tissue architecture

61
Q

Describe retraction and re-canalisation?

A

Thrombus and clots can both shrink - allowing space within the vessel, blood can move past

62
Q

Describe organisation and scarring?

A

Organised by fibroblasts causing scarring and reducing blood flow

63
Q

Describe embolism?

A

Thrombus breaks off and moves passively through the circulation

64
Q

What are the majority of emboli?

A

Fragments of thrombus

65
Q

Other than fragments of thrombi what can embolism be made of?

A

Atheromatous debris, vegetations on heart valves, fat, tumours

66
Q

Where do pulmonary embolisms occur?

A

Venous side - legs (deep vein thrombosis) and pelvic veins

67
Q

How does the size of the embolus effect consequences of pulmonary embolisms?

A
Big = could block pulmonary artery = sudden death
Small = smaller arteries = chest pain breathlessness, hypertension
68
Q

Why does systemic embolism occur?

A

Thrombosis in left side of heart or aterial system

69
Q

What do the consequences of systemic embolism depend on?

A

Size and site the thrombus lodges

70
Q

What causes infarction?

A

Atheromas, thrombosis, embolism, vasculitis, compression, spasm, hyperviscosity

71
Q

What determines infarction?

A

Vascular anatomy
Duration of occlusion (length of time the thrombus is there)
Metabolic requirements of tissue - brain has high requirements for glucose and oxygen - few minutes = death)
general circulatory factors - reduction in nutrients due tot heart failure
Reperfusion

72
Q

What can cause aneurysms?

A

Atherosclerosis

Mycotic - infection