3.1 haemostasis

Question 1

the arrest of bleeding and maintenance of vascular patency

Answer 1

haemostasis

Question 2

consequences of failure of platelet plug formation

Answer 2

bruising and purpura
mucosal; epistaxis, GI bleeding, conjunctival bleeding, menorrhagia
intracranial haemorrhage
retinal haemorrhage

Question 3

screening test for primary haemostasis

Answer 3

platelet count

Question 4

extrinsic pathway clotting factors; these initiate secondary haemostasis

Answer 4

TF/ VIIa

Question 5

amplification of secondary haemostasis

Answer 5

VIII/IXa

Question 6

measures the extrinsic pathway, used in warfarin

Answer 6

PT, INR

prothrombin time

Question 7

measures the intrinsic pathway, used in heparin

Answer 7

aPTT

Question 8

where does antithrombin act to inhibit clotting factors?

Answer 8

TF/VIIa 
V/Xa 
VIII/IXa 
thrombin 
all inhibited

Question 9

where does protein C/S act to inhibit clotting factors?

Answer 9

V/Xa

VIII/IXa

Question 10

what activates protein C/S?

Answer 10

thrombin (bound to thrombomodulin on the surface of endothelial cells)