Arterial and Venous thrombosis Flashcards

1
Q

What is the difference between a clot in a living and a dead person + why

A

Living - one layer
Dead - red cells tend to settle out before clot forms so we have two layers: Lower deep-red and upper clearer with platelets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does the clot in a dead person take the shape of

A

The shape of the vessel in which they have formed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does the clot formed in a dead person break down

A

Hydrolysis by enzymes released by cells of the vessel wall and RBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a thrombus

A

Solidification of blood contents that form within the vascular system during life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the role of a platelet

A

Closing small gaps in vessel walls through trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are platelets derived from

A

Megakaryocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What structures can be found in platelets

A
  1. Mitochondria
  2. Cytoskeleton
  3. Alpha granules
  4. Dense granules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do alpha granules in platelets contain

A

Fibrinogen, Fibronectin, Platelet growth factor and anti heparin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are found in dense granules of platelets

A

ATP and ADP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Role of ATP and ADP in clotting

A

Platelet aggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the result of the platelet cascade forming in an intact non-damaged vessel

A

Thrombus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What three ways can a thrombus form

A
  1. Changes in intimal surface of vessel
  2. Changes in pattern of blood flow
  3. Changes in blood constituents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What three ways can a thrombus form

A
  1. Changes in intimal surface of vessel
  2. Changes in pattern of blood flow
  3. Changes in blood constituents

^ Virchow’s triad

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does an atheromatous plaque cause arterial thrombosis

A
  1. Plaque enlarges
  2. Plaque protrudes into lumen
  3. Disrupts blood flow.
  4. Causes loss of intimal cells
  5. Denuded plaque surface is presented to platelets
  6. Causes fibrin deposition and platelet clumping
  7. Bare luminal surface of vessel will have exposed collagen and platelets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does an atheromatous plaque cause arterial thrombosis

A
  1. Plaque enlarges
  2. Plaque protrudes into lumen
  3. Disrupts blood flow.
  4. Causes loss of intimal cells
  5. Denuded plaque surface is presented to platelets
  6. Causes fibrin deposition and platelet clumping
  7. Bare luminal surface of vessel will have exposed as endothelial cells lining vessel are damaged to collagen and platelets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What two of the three Virchow’s triad can apply to arterial thrombosis and under what conditions

A
  1. 3rd - Plaque is in aorta of the smoker or someone with high cholesterol / LPL as there is a change in blood constituents
    (book didn’t mention the other one lol)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why is arterial thrombosis in the aorta of a smoker / high LPL self-perpetuating

A

Platelet growth factor contained in alpha granules causes proliferation of arterial smooth muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do atheromatous plaque mostly consist of

A

Arterial smooth muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the first layer of a thrombus made of

A

Platelets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is and how does the second layer of a thrombus develop

A
  1. Red blood cells

2. Precipitation of fibrin meshwork traps red blood cells above platelet layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the alternating layer of a thrombus called

A

Lines of Zahn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In which direction will the thrombus grow in

A

Direction of the blood flow - propagation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why does an atheroma not occur in veins

A

Low pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How does venous thrombosis occur

A
  1. Presence of valves causing disturbances or exposed to trauma
    2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How do venous thrombosis occur

A
  1. Blood pressure falls during surgery or heart attack slowing blood flow
  2. Venous return slows down due to lack of calf muscle contractions (DEEP VEIN THROMBOSIS)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What symptoms would I be looking for in people with arterial thrombosis

A
  1. Loss of pulse distal to thrombus

2. Signs of impaired blood supply (cold, ,pain and pale in area)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What symptoms would I be looking for in individuals with venous thromboses

A

Area becomes swollen, tender and red as blood is still being taken to site but not drained by veins.

28
Q

Why is the site tender during vein thromboses

A

Because ischaemia is developing in vein wall

29
Q

How do myocardial infarctions result in a death

A

Thrombus formation in coronary arteries

30
Q

How does a thrombus lead to a stroke

A

Forms in cerebral vessel

31
Q

What three things can happen to a thrombus

A
  1. Resolve
  2. Organised into scar by macrophages (clear thrombus) and fibroblasts (collagen)
  3. Intimal cells of vessel proliferate and capillaries grow into thrombus, recanalising the occlusion
  4. Death (occludes vital organ)
  5. Embolism
32
Q

What is an embolism

A

Mass material in circulatory system that can get lodged in vessel and block lumen

33
Q

How are most embolisms caused

A

By thrombus

34
Q

Where do most venous thromboses form

A

Leg veins (95%) / pelvic veins / Intracranial sinuses

35
Q

How does a pulmonary embolism form

A

Thromboses from areas where a venous thromboses has occurred will enter pulmonary system

36
Q

Can an organised thrombus cause a pulmonary embolism

A

Yes but it is not severe if the thrombus is small but these are permanent and may cause small respiratory deficiency

37
Q

Can an organised thrombus become severe

A

Yes, due to an accumulation of small, organised thrombus forming in long-term

38
Q

What is an accumulation of tiny embolic events in the pulmonary system going to lead to

A

Damage - idiopathic pulmonary hypertension

39
Q

What is the result of 2nd class embolisms in the pulmonary system

A

Acute respiratory and cardiac problems

40
Q

What are the symptoms of 2nd class pulmonary embolisms

A

Chest pain

Shortness of breath

41
Q

Why can a pulmonary embolism cause shortness of breath

A

Occluded vessel supplying lung infarcting the area

42
Q

What is the long-term effect of 2nd class pulmonary embolisms

A

Recurrent episodes even if most people recover and lung function is impaired

43
Q

What do 3rd class pulmonary embolisms result in

A

death

44
Q

Where do 3rd class pulmonary embolisms come from

A

Leg veins (have same shape as the vessels they arose from)

45
Q

Where are thrombi in 3rd class embolisms found

A

At bifurcation of a major pulmonary artery

46
Q

Where do systemic embolisms arise from

A

Arterial system (heart or atheromatous plaque)

47
Q

Where may a thrombi form in the heart

A

Areas of cardiac muscle that have died due to myocardial infarction

48
Q

How would a thrombi form in the heart

A

Loss of normal endothelial lining and exposure of underlying collagen to platelets
Dead myocardium disrupts blood flow

49
Q

What condition may cause thrombosis within the heart

A

fibrillation

50
Q

How does atrial fibrillation cause a thrombi to form

A

stagnates blood in atrial appendages, when heart rhythm normalises, fragment breaks off

51
Q

In what chamber of the heart to emboli originate from

A

left atrium or left ventricle

52
Q

What is the consequence of the emboli originating from the left ventricle and atrium

A

Can travel to anywhere in the systemic circulation (e.g. brain vessels)

53
Q

Where may a large emboli from the heart lodge at

A

bifurcation of aorta cutting supply to lower or upper limbs (needs quick diagnosis before it can’t be reversed)

54
Q

What is the effect of smaller emboli

A
  1. lodge in peripheral vessels

2. Cause gangrene in fingers

55
Q

What drug stops platelet aggregation

A

Aspirin

56
Q

Define infarction

A

reduction in blood flow and subsequent death of cells

57
Q

What is the impact of a small emboli travelling to the kidney

A

It asymptomatic

Causes death in area distal to site of impaction

58
Q

What is the result of an emboli travelling to the intestines

A

Death of whole sections of bowel due to superior mesenteric artery block

59
Q

What is an embolic atheroma

A

Fragments of atheromatic plaque embossing in the lower limbs (e.g. causing ischaemic toes)

60
Q

What is a platelet emboli

A

Platelet deposition in early stages of atheroma formation can break off

61
Q

Are platelet emboli dangerous

A

No unless they enter the brain vessels = TIA

62
Q

What are fat embolisms

A

Severe trauma to long bones causes fat from marrow to release into circulatory systems.

63
Q

What are gas embolisms

A

When we go from high-to-low pressure environments

Nitrogen bubbles form during decompression and enter bones/joints (pain)

64
Q

What is an amniotic embolism

A

During labour, increased pressures in the uterus causes amniotic fluid to travel into the circulation and LODGE into the lungs (pulmonary embolism)

65
Q

What is a tumour embolism

A

Tumour fragments break off (not a big deal)