5 Haemostasis + thrombosis

Question 1

what is the role of vessel wall in haemostasis?

Answer 1

To constrict and reduce blood loss

Question 2

Wha is the role of platelets in haemostasis?

Answer 2

To adhere together and form platelet plug

Question 3

What is the role of coagulation system in haemostasis?

Answer 3

to activate the clotting cascade/ and convert inactive proteins to activated form: prothrombin –> thrombin, fibrinogen –> fibrin

Question 4

What is fibrinolysis and describe the process

Answer 4

Breakdown of fibrin (mesh0, Plasminogen converted to plasmin (breaks down mesh) by streptokinase + t-PA

Question 5

Which factors control coagulation?

Answer 5

Thrombin inhibitors:
1. anti-thrombin III
2. alpha 1 anti-trypsin
3. alpha 2 macroglobulin
4. proteins C + S
deficiency of 1 and 4 leads to thrombosis

Question 6

Name 4 anti-thombin produced by the endothelium

Answer 6

1. Plasminogen activator (breaks down fibrin mesh)
2. Prostacyclin
3. thombomodulin
4. nitric oxide

Question 7

What is thrombosis?

Answer 7

the formation of a solid mass of blood in the circulatory system DURING LIFE

Question 8

Name 3 predisposing abnormalities of thrombosis

Answer 8

1. Vessel Wall
2. Blood flow
3. blood components

Question 9

What abnormalities of vessel wall can cause thrombosis?

Answer 9

Atheroma (fatty deposits, narrowing lumen), direct injury and inflammation (vasculitis)

Question 10

What abnormalities of blood flow can lead to thrombosis?

Answer 10

Stagnation (stationary flow), turbulence (high resistance)

Question 11

What abnormal blood components can predispose thrombosis?

Answer 11

smokers (thicker blood, coagulate easier), post- partum (giving birth, need to clot easier), post-operation

Question 12

What are the 5 outcomes of thrombosis?

Answer 12

Resolution, propagation, organisation, recanalisation, embolism

Question 13

What is resolution?

Answer 13

Thrombus dissolves (usually v small)

Question 14

What is propagation?

Answer 14

Thrombus spread + grow in direction of travel e.g. arteries (distal), veins (proximal)

Question 15

What is organisation?

Answer 15

ingrowth of fibroblast

Question 16

What is recanalisation?

Answer 16

Small holes created in thrombus to allow blood through, thrombus is still lodging in vessel

Question 17

What is embolism?

Answer 17

lodging of blood clot blocking blood vessel at site away from origin, by solid / liquid / gas

Question 18

What is Virchow’s triad?

Answer 18

3 actors contributing to thrombosis: hypercoagulability (clots easily), hemodynamic changes (abnormal blood flow), endothelial injury / disfunction (vessel wall injury)

Question 19

Name some effects of thrombosis

Answer 19

ischaemia + infarction, in veins can cause oedema and congestion

Question 20

What is embolism?

Answer 20

Blockage of blood vessel by solid/ liquid/ gas at site away from origin

Question 21

What is pulmonary embolism?

Answer 21

Embolism in veins going to lungs

Question 22

Name some examples of venous + arterial embolism?

Answer 22

heart –> artoa –> other arteries
arteromatous carotid arteries –> brain
artheromatous abdominal aorta –> arteries in the legs

Question 23

What is deep vein thrombosis?

Answer 23

Blood clot in deep veins, commonly in legs

Question 24

What are predisposing factors of deep vein thrombosis?

Answer 24

immobility (e.g. bed-bound), post-op, post-partum, oral contraceptives, severe burns, cardiac failure, disseminated cancer
also in long journeys where legs are compressed

Question 25

What would be used in prevention of thromboembolic disease?

Answer 25

prophylaxis

Question 26

what would be used to treat thromboembolic disease?

Answer 26

IV heparin + oral warfarin

Question 27

What are other types of embolisms that can occur? (apart from deep vein and venous + arterial)

Answer 27

air, amniotic fluid, fat, medical equipment, tumour cells

Question 28

Name the 3 types of haemophilia and the defects they are linked to

Answer 28

haemophilia A - factor 8 deficiency haemophilia B - factor 9 deficiency haemophilia C - factor 11 deficiency all part of intrinsic pathway, leading to blood clots not formed as readily and easy bruise

Question 29

What is disseminated intravascular coagulation?

Answer 29

Widespread activation of clotting cascade leading blood clot in small vessels

Question 30

What is thrombocytopenia?

Answer 30

Deficiency of platelets, can't clot as platelet plug can be form, easily bruises

Question 31

What is thrombophilia?

Answer 31

Blood clots easily, can increase chances of DVT and or PE

Question 32

Name some symptoms of pulmonary embolism

Answer 32

shortness of breathe, small peripheral arteries blocked, if recurrent leads to pulmonary hypertension

Question 33

what is haemostasis?

Answer 33

body's response to damaged blood vessels' forms blood clot to stop bleeding