Haemostasis and Thrombosis

Question 1

Haemostasis is the prevention of ???from damaged blood vessels

Answer 1

blood loss

Question 2

Damage from a wound causes ???, adhesion and activation of platelets and formation of fibrin.

Answer 2

vasoconstriction

Question 3

what forms a thrombosis?

Answer 3

Platelet activation and fibrin formation forms

Question 4

three factors that predispose to thrombosis (Virchow triad): injury to the vessel wall, altered blood flow, and ???

Answer 4

abnormal coagulability

Question 5

Blood coagulation involves the conversion of fibrinogen to fibrin by ??? (which can also cause platelet activation)

Answer 5

thrombin

Question 6

??? is released following tissue damage to initiate blood coagulation

Answer 6

tissue factor

Question 7

??? is a natural inhibitor of blood coagulation to prevent continual activation of this pathway

Answer 7

Antithrombin III

Question 8

??? is an inherited disorder of increased coagulability

Answer 8

Thrombophilia

Question 9

??? is an inherited disorder of decreased coagulability

Answer 9

Haemophilia

Question 10

??? is a disease comprised mainly of platelets and fibrin, and usually associated with atherosclerosis

Answer 10

Arterial thrombosis

Question 11

Venous thrombosis (or ‘blood clot’): comprised mainly of RBCs and ???. Can move through blood stream to form an embolus in the lung, heart, brain or other organ to cause ischaemia or infarction

Answer 11

fibrin

Question 12

Membrane-bound ??? provides a non-thrombogenic surface on vascular endothelium, preventing platelet activation and coagulation

Answer 12

heparan sulfate

Question 13

Vascular endothelium synthesizes
- Antithrombotic factors including ???
- Prothrombotic factors including ???

Answer 13

• prostaglandin I2, nitric oxide, adenosine, tissue plasminogen
  activator and thrombomodulin (a thrombin receptor)
• von Willebrand factor, tissue factor and plasminogen activator inhibitor (PAI-1)

Question 14

Bacterial endotoxin and host cytokines alter antithrombotic and prothrombotic states of endothelium = promote disseminated intravascular coagulation in ???, ??? and other states

Answer 14

sepsis,
cancer

Question 15

Drugs are used to treat or prevent thrombosis/ thromboembolism, targeting three distinct pathways:
1. Blood coagulation (fibrin formation)
2. Platelet function
3. ??? removal

Answer 15

Fibrin removal

Question 16

Coagulation Cascade INTRINSIC or EXTRINSIC pathway: AKA the contact pathway. Activated by contact with artificial surfaces or exposed collagen, DNA, RNA or polyphosphates in damaged endothelium. No contribution to haemostasis in vivo

Answer 16

intrinsic

Question 17

Coagulation Cascade INTRINSIC or EXTRINSIC pathway: AKA the in vivo or tissue factor (TF) pathway. TF abundant in adventitial cells surrounding blood vessels larger than capillaries, and in epithelial cells surrounding tissues

Answer 17

extrinsic

Question 18

drugs that act on coagulation cascade (clotting effects): Factor VIII or IX is used to treat ???

Answer 18

haemophilia

Question 19

drugs that act on coagulation cascade (clotting effects): recombinant factor VIIa is used to treat ???

Answer 19

severe bleeding

Question 20

drugs that act on coagulation cascade (clotting effects): Vitamin K is used for excessive anticoagulation therapy (e.g. warfarin) and prevention of ??? disease in newborns

Answer 20

haemorrhagic disease

Question 21

vitamin K promotes the carboxylation of ??? as it is a lipid soluble vitamin essential as a cofactor in the formation of this.

Answer 21

clotting factors

Question 22

Drugs that Act on the Coagulation Cascade (Venous Thrombosis): heparin and low molecular weight heparins prevent/treat ??? but can cause haemorrhage, osteoporosis

Answer 22

thrombosis

Question 23

Drugs that Act on the Coagulation Cascade (Venous Thrombosis): ??? is used to prevent/treat venous thrombosis as well as myocardial damage in angina and myocardial infarction. can cause haemorrhage and necrosis

Answer 23

warfarin

Question 24

Drugs that Act on the Coagulation Cascade (Venous Thrombosis): Direct inhibitors of thrombin, prevent or treat venous throkmbosis but can cause minor haemorrhage and ???

Answer 24

gastrointestinal disturbances

Question 25

heparin inhibits coagulation by activating ???

Answer 25

antithrombin III

Question 26

Heparin and LMW heparin increase the inhibitory effect of ??? on factor IIa (thrombin) by binding both ??? and IIa = inhibit coagulation

Answer 26

antithrombin III

Question 27

TRUE or FALSE: Heparin increases the inhibitory effect of AT III on Factor Xa by binding only AT III

Answer 27

TRUE

Question 28

Warfarin inhibits ??? to reduce the reduced form of Active Vitamin K and the carboxylation of clotting factors

Answer 28

Vitamin K Reductase

Question 29

Warfarin is metabolised by cytochrome P450 family 2 subfamily C member 9 (CYP2C9), which is polymorphic with varying activity between individuals. Use of warfarin requires monitoring to prevent ???

Answer 29

bleeding (haemorrhage)

Question 30

Drugs that Alter Warfarin Activity: NSAIDS (aspirin); antibiotics (moxalactam, carbenicillin) all inhibit platelets and INCREASE or DECREASE warfarin action?

Answer 30

increase

Question 31

Drugs that Alter Warfarin Activity: cephalosporins inhibit ??? reduction, increasing warfarin activity

Answer 31

vitamin k

Question 32

Drugs that Alter Warfarin Activity: vitamin K causes coagulant activity opposing anticoagulant actIvIty of warfarin = INCREASE or DECREASE IN WARFARIN ACTIVITY?

Answer 32

DECREASE

Question 33

TRUE or FALSE: anticoagulant drugs act on sites of factor XIIa, XIa, IXa, Xa, IIa, XIIIa

Answer 33

true

Question 34

platelet activation: 1. ruptured plaque or tissue damage = adhesion of platelets to ??? surface = activation

Answer 34

thrombogenic

Question 35

platelet activation: 2. ??? = activation of platelets

Answer 35

thrombin

Question 36

platelet activation can lead to Arachadonic Acid generation = production of cyclic endoperoxidases = synthesis of TXA2 = expression of GP IIb/IIIa receptors = linkage of adjacent platelets by fibrinogen binding = ???

Answer 36

aggregation of platelets

Question 37

aspirin impairs ??? activity by inhibiting cyclogenase-1 and thromboxane A2 synthesis to prevent thrombotic stroke and heart attack

Answer 37

platelet activity

Question 38

dipyridamole inhibits ??? aggregation to reduce risk of stroke and death during ischaemic attacks

Answer 38

platelets

Question 39

Clopidogrel, prasugrel and ticagrelor are drugs that impair platelet activity by inhibiting ??? receptors for acute coronary syndromes

Answer 39

P2Y12 receptors

Question 40

aspirin reduces the action of ??? triggering production of cyclic endoperoxides to work as an antiplatelet drug

Answer 40

arachadonic acid

Question 41

drugs that promote fibrinolysis (thrombolysis): streptokinase activates ??? to reduce myocardial infarction, thrombotic stroke, etc

Answer 41

plasminogen