Haemostasis

Question 1

name components lining the endothelium which allow nnormal blood flow/ stop coag?

Answer 1

NO, Heparins, TFPI, Thrombomodulin, prostacyclin

Question 2

wahta re the signals for activating platelets and coag factors?

Answer 2

abnormal cell surface, physiological activator

Question 3

what does the open canillicular system allow?

Answer 3

SECRETION OF INTERNAL COMPONENTS

Question 4

what do Alpha granules secrete?

Answer 4

Von Willebrand Factor and Thrombin

Question 5

what do dense granules secrete?

Answer 5

ADP/ATP, Ca, Serotonin

Question 6

how does adhereance of platelets occur?

Answer 6

VWF to GP1b, thrombin to GP1a, fibrinogen to GP2b

Question 7

how does asprin work?

Answer 7

stops platelets aggregating

Question 8

what is the role of platelets in haemostasis?

Answer 8

adhere, activation, aggregation and provide a phosphilipid surface for coagulation.

Question 9

VWF binding sites

Answer 9

binds Patelets to collagen

Question 10

what happens to fibrinogem to allow the cascade to complete?

Answer 10

cleaved by the prothrombin –> thrombin activation (domino cascade)

Question 11

what may stop the cascade?

Answer 11

Haemophilia or anticoag drugs.

Question 12

3 key natural anticoagulants (how do they each work)?

Answer 12

tissue factor pathway inhibitor, activated protein C and S, Antithrombin

Question 13

outline Fibrinolysis

Answer 13

endothelium produced TPA (proteases) and UPA, (plasminogen activators) - TPA cleaves plasminogen into plasmin - this fragments the clot - producing fibrin degredation products e.g. D-Dimer

Question 14

what does ASPRIN do?

Answer 14

REDUCES PLATLET AGGREGATION - inhibits cyclooxygenase from working, inhibits arachadonic acid from turning into thrmoboxane A2.

Question 15

what drugs stop ADP from starting the aggregation in platelets?

Answer 15

Clopidogrel, Prasugrel, Ticagrelor

Question 16

which drugs prevent the binding of fibrinogen to GP2b/a?

Answer 16

Abciximab, Tirofiban, Eptifibatide

Question 17

Anticoagulant - WARFARIN

Answer 17

it is a vitmain K antagonist thus it inhibits Factors 2,7,9,10 from being carboxylated- Prevents the post translation of these factors from being activated .

Question 18

Anticoagulant - HEPAIRN

Answer 18

binds to antithrombin, increases its activity - preventing thrombin formation

Question 19

what drugs effect factor 10a? - anticoagulants such as…

Answer 19

Rivaroxaban, Edoxaban, Apixaban

Question 20

what is the target INR

Answer 20

2 to 3

Question 21

how would you commence someone of warfarin?

Answer 21

take a basline inr, then commence on iv warfarin until inr reaches therapeutic level over 2 days.

Question 22

if INR is 9.7 and there is bleeding what would you do?

Answer 22

control bleeding, give vit k, withhold warfarin until the inr has stabilised

Question 23

name 3 antiplatelet drugs

Answer 23

asprin, clopidorgel, dipyridamole, adciximab, the BANS.

Question 24

what drugs decrease the activity of warfarin?

Answer 24

antibiotics, laxatives, cimetidine, phenylbutazone

Question 25

what drugs incrrase the activity of warfarin?

Answer 25

asprin, antiplatelet drugs, alcohol.