93. thrombosis, embolism and infarction

Question 1

are blood clots and thrombosis the same thing

Answer 1

NO

Question 2

where can you see blood clots

Answer 2

bruising etc

Question 3

blood clot extravascular or intravascular

Answer 3

extravascular

Question 4

what substances are involved in a blood clot

Answer 4

RBCs, fibrin, platelets etc

Question 5

thrombus extravascular or intravascular

Answer 5

intravascular

Question 6

Do thrombosis move around and circulate

Answer 6

NO - they are static

Question 7

thrombosis - trigger of coagulation where?

Answer 7

WITHIN a blood vessel

Question 8

what is thrombosis

Answer 8

excess intravascular coagulation

Question 9

what is the end point of coagulation

Answer 9

aggregate of platelets, RBCs and fibrin etc

Question 10

in coagulation what binds everything together

Answer 10

fibrin

Question 11

what are the types of pathways in coagulation cascades

Answer 11

intrinsic
extrinsic
common

Question 12

what is extrinsic pathway in coagulation cascade

Answer 12

produced through tissue factor
Factor 7 - factor 7a
which acts on
Factor 10- factor 10a
which acts on
prothrombin to thrombin
which acts on
fibrinogen to fibrin

Question 13

which is more common in the coagulation cascade. The Intrinsic pathway or the extrinsic pathway

Answer 13

extrinsic

Question 14

what is intrinsic pathway in coagulation cascade

Answer 14

produced through contact activation
Factor 12 - factor 12a
which acts on
Factor 11- factor 11a
which acts on
Factor 9 - factor 9a
which acts on
Factor 10 to 10a
prothrombin to thrombin
which acts on
fibrinogen to fibrin

Question 15

explain the common cascade of coagulation

Answer 15

Factor 8 - factor 8a
which acts on
Factor 10 to 10a
prothrombin to thrombin
which acts on
fibrinogen to fibrin

Question 16

what is the intrinsic coagulation cascade blood test

Answer 16

Prothrombin Time (PT)

Question 17

what is the extrinsic coagulation cascade blood test

Answer 17

activated partial thromboplastin Time (APTT)

Question 18

what does fibrin do?

Answer 18

binds everything together by forming the mesh of the net

Question 19

thrombosis can occur anywhere but if favoured in locations with what 3 characteristics

Answer 19

1. sites of endothelial injury
2. turbulent blood flow
3. hypercoagulative blood

Question 20

1. Sites of endothelial injury
2. Turbulent blood flow
3. Hypercoagulable blood
   these together are known as…..

Answer 20

Virchow’s Triad

Question 21

why would hypertension be associated with endothelial injury

Answer 21

lots of banging on the side of the vessel walls

Question 22

what is primary vasculitis

Answer 22

autoimmune disease characterised by inflammation directed at vessel walls. specific antibodies.

Question 23

what are some things that contribute to endothelial injury

Answer 23

• Hypertension
• Increased exposure to tissue factor
• Weak vessel walls
• Atheroma
• Aneurysms
• Lots of surface thrombosis
• Autoimmune disease
• Primary vasculitis
• Turbulence
• Stasis

Question 24

describe laminar blood flow

Answer 24

most constituents are in center of vessel with slow flowing plasma peripherally

Question 25

what is stasis

Answer 25

slowing or stagnation of blood circulation in blood vessels

Question 26

what is hypercoagulability

Answer 26

increased tendency to develop blood clots

Question 27

what causes hyperrcoaguability

Answer 27

lots and lots of causes - anything causing increased viscosity

Question 28

name some of the inherited disorders - primary causes

Answer 28

- factor V Lieden - Protein C deficiency - Protein S deficiency - Antithrombin III deficiency

Question 29

name some of the inherited disorders - secondary causes

Answer 29

- Prolonged immobility - Significant tissue injury – burns, RTA - Antiphospholipid syndrome –autoimmune - Myocardial infarction - Atrial fibrillation (irregular cardiac rhythm) - cancer - therapy - marantic endocarditus

Question 30

how is cancer a secondary cause of thrombosis

Answer 30

activate coagulation cascade through tumour produced TF, mucin, inflammatory cytokines

Question 31

how is therapy a secondary cause of thrombosis

Answer 31

many chemotherapeutic agents injure endothelium and increase risk of thrombosis

Question 32

what is an embolism

Answer 32

a thrombus that has been transported through the vasculature to a point where it gets stuck

Question 33

most thrombosis is ... arterial or venous?

Answer 33

venous

Question 34

what is ischaemia

Answer 34

insufficient blood supply

Question 35

what is infarction

Answer 35

death of tissue as a result of ischaemia

Question 36

How does hypoxia cause cell injury and then acute inflammation?

Answer 36

No oxygen = no ATP

Question 37

what is ATP used for

Answer 37

- ATP is the basic unit of currency for cellular energy - ATP is required for anything that is not passive - ATP required for most ion channel pumps - Na/K ATPase - Ca channels

Question 38

what if there is no ATP

Answer 38

- Increased calcium stimulates 1. ATPase (makes things worse) 2. Phospholipase (membrane damage) 3. Proteases (membrane and cytoskeleton damage) 4. Endonuclease (DNA damage and breakdown) Mitochondrial permeability (release pro death factors

Question 39

are embolisms just blood constituents

Answer 39

no

Question 40

what are the different types of embolism

Answer 40

amniotic fluid fat tumour blood septic air

Question 41

how much air is needed to get a air embolism

Answer 41

100ml

Question 42

breathing at high pressure (like diving in sea) results in what

Answer 42

more dissolved gas

Question 43

Breathing at high pressure results in more dissolved gas. As pressure reduces .............. comes out of solution

Answer 43

Nitrogen

Question 44

- Breathing at high pressure results in more dissolved gas - As pressure reduces nitrogen comes out of solution Multiple bubbles which causes......? and what is this process called

Answer 44

decompression sickness the bends

Question 45

explain amniotic fluid embolism

Answer 45

A rare complication of childbirth Tear in placenta or uterine vessels with secondary infusion of amniotic fluid or fetal material Identify fetal skin (squamous cells) and hair etc in pulmonary vessels

Question 46

what is a fat embolism made of

Answer 46

fat and marrow

Question 47

after what kind of injury does fat embolisms occur

Answer 47

skeletal muscle injuries

Question 48

large or small amounts of patients are symptomatic after injury (fat embolism)

Answer 48

small

Question 49

describe a tumour emboli

Answer 49

- Usually associated with true thrombus - Tumours are thrombogenic - Some tumours have a propensity for vascular invasion - Tumours are often friable by their nature Failed metastases?

Question 50

describe septic emboli

Answer 50

- Specific intravascular infections - Thrombus forms in association with an infectious agent - Abnormal cardiac valves - Mycotic aneurysm - In the heart – infective endocarditis - Symptoms from numerous septic emboli