1. Atheroma Thrombosis And Embolism

Question 1

What is an atheroma and what does it consist of

Answer 1

• Lesion in the intima that protrudes into a vessel wall
• soft core of lipid (mainly cholesterol and cholesterol esters)
• fibrous cap

Question 2

What are foam cells

Answer 2

Macrophages that have engulfed lipid

Question 3

What is the fibrous cap of an atheroma made up of

Answer 3

Macrophages, lymphocytes and foam cells and collagen and elastin

Question 4

What is the necrotic centra of an atheroma made up of

Answer 4

Cell debris, cholesterol crystals, foam cells, calcium

Question 5

What kind of vessels may be commonly affected by atherosclerosis

Answer 5

Bifurcation (normally sites of turbulent blood flow)
Abdom aorta
Coronary/ popliteal/ corotid arteries
Circle of Willis

Question 6

Give three examples of non-modifiable risk factors of atheroma

Answer 6

Increasing age
Male gender
Family history

Question 7

Give examples of modifiable risk factors for atheroma

Answer 7

Hyperlipidemia 
Hypertension 
Diabetes 
Smoking 
(Can damage the endothelium)

Question 8

What are the main steps that lead to an atheroma

Response to injury hypothesis

Answer 8

1. Damage/ injury to the inner layer of an artery (due to to diabetes or irritants such as nicotine
2. Allows influx of cells and lipids into the intima
3. Cells such as macrophages or smooth muscle cells often recruited from underlying media - try to engulf the lipids
4. These become foam cells n die
5. Excess of extracellular lipid
6. Smooth muscle cells try to lay down collagen
7. Form an overlying cap over this lipid pool
8. Protrudes into the lumen of vessel

Question 9

What is the primary cause of atherosclerosis developing

Answer 9

Endothelial injury to the arterial wall (leads to chronic inflammatory response)

Question 10

What is the earliest lesions of atherosclerosis

Answer 10

Fatty streak

Question 11

What is a fatty streak composed of

Answer 11

Lipid filled foamy macrophages - eventually collapse into streaks
Can be normal/common
Not significantly raised so dont cause flow disturbance

Question 12

How is the atherosclerotic plaque formed

Answer 12

When the intima thickens - lipid accumulates
Appears white/ yellow raised plaques
Impinges on vessel lumen

Question 13

Give 4 consequences of atherosclerosis

Answer 13

1. Lesion could rupture, ulcerated, erode- integral surface is then exposed to blood, thrombogenic substances, induced thrombosis
2. Heammorhage into plaque
3. Atheromembolism
4. Aneurysm formation (artery wall swelling) due to pressure, recruiting cells, chemical factors

Question 14

What isa thrombus

Answer 14

Solid mass of blood constituents formed within the vascular system

Question 15

What is venous thrombosis mostly due to

Answer 15

Stasis

Question 16

What are the three factors in Virchow’s Triad

Answer 16

Endothelial injury
Abnormal blood flow (turbulence/ stasis)
Hypercoagulobility

Question 17

What is claudication

Answer 17

Pain on walking due to reduced blood flow to legs

Question 18

In which way is an arterial thrombosis mostly formed

Answer 18

From rupture of atheromatous plaque

Question 19

Typical causes of venous thrombosis

Answer 19

Combination of factors from virchows triad

Question 20

Why are venous sinusoids common locations of venous thrombosis

Answer 20

They allow pooling of blood

Question 21

Is acute coronary syndrome caused by arterial of venous thrombosis

Answer 21

Arterial

Question 22

Is claudication and ishchamic stroke caused by arterial or venous thrombosis

Answer 22

Arterial

Question 23

What is the main composition of an arterial thrombus

Answer 23

Mainly platelets

Question 24

Main composition of venous thrombus

Answer 24

Fibrin

Question 25

What is the treatment for arterial thrombosis

Answer 25

Anti- platelet

Question 26

Example of an anti platelet agent

Answer 26

Clopidogrel

Question 27

Treatment for venous thrombosis

Answer 27

Anticoagulants eg warfarin heparin

Question 28

What faactors can cause endothelial damage

Answer 28

Smoking Hypertension Surgery Trauma

Question 29

What are some heridtary factors that cause hypercogulobility

Answer 29

—Factor v Lieden (part of clotting cascade, resistant to cleavage by Protein C) —Prothrombin G20210A (causes increased conversion of fribongen to fibrin) —Protein C and S deficiency (cleave factors 5 and 8 which are brakes for the clotting cascade)

Question 30

Give some exposes of acquired factors that cause hypercoagulobility

Answer 30

``` Cancer OCR/ HRT Pregnancy Obesity HIT = Heparin Induced Thrombocytopenia ```

Question 31

Difference between clot n thrombus

Answer 31

``` Clot = settling of RBCs, hardened blood, can occur outside vessel (test tube/ haematoma) as well as inside (post-mortem) Thrombus = during life, occurs ONLY inside vessel ```

Question 32

Are platelets involved in clot or thrombus

Answer 32

Only thrombus

Question 33

What are lines of Zahn

Answer 33

Pale lines seen in a thrombus | Represent platelets and fibrin

Question 34

Give some consequences of thrombosis

Answer 34

``` Occuslion of vessel Dissolution Incorporation into vessel wall -narrowing of lumen Recanalisation Embolisation ```

Question 35

What’s an embolus

Answer 35

Mass of material in the vascular system able to become lodged in the vessel and block its lumen

Question 36

What are emboli derived from

Answer 36

Mostly from thrombi

Question 37

How are pulmonary emboli most commonly formed

Answer 37

Derived from DVT = thrombus in leg breaks off, goes through venous system to right side of heart, into pulmonary arteries

Question 38

Where do systemic emboli arise from

Answer 38

Arterial system

Question 39

What is a paradoxical embolus

Answer 39

Thrombus which arises in the venous system of the body and is able to travel into the heart, go through a septal defect into the left side and access the arterial circulation.