part 9

Question 1

thrombin

Answer 1

coagulation factor IIa

removes fibrinopeptides from E-domain, creates fibrine polymers

Question 2

fibrinogen

Answer 2

coagulation factor I

Question 3

factor XIII

Answer 3

creates crosslinks between fibrin polymers
activated by thrombin
when activated: transforms fibrinogen into fibrin

Question 4

generation of thrombin: extrinsic pathway

Answer 4

upon contact w/ TF

Question 5

generation of thrombin: intrinsic pathway

Answer 5

upon contact w/ foreign surfaces (like glass)

Question 6

Tissue Factor

Answer 6

= transmembrane GP
= non-enzymatic cofactor of factor VIIa
normally absent in blood
produced by fibroblasts + SMC
expressed on monocytes + epithelial cells during inflammation
in cancer: expressed on tumor cells and tumor derived particles

Question 7

prothrombin time

Answer 7

= INR
measures extrinsic pathway
measures clotting time in sec
take citrated plasma, add TF + phospholipids + Ca

Question 8

aPTT

Answer 8

measures intrinsic pathway
measures clotting time in sec
take citrated plasma, add glass + phospholipids + Ca

Question 9

factor VIII

Answer 9

availability determined by vWF

Question 10

abnormal primary hemostasis

Answer 10

gives: petechia,
increased bleeding time,
normal PT
normal aPPT

Question 11

abnormal secondary hemostasis

Answer 11

hematosis in joints etc
normal bleeding time
re-bleeding
prolonged PT and/or aPTT

Question 12

FVIII defect

Answer 12

gives haemophilia A

X-linked

Question 13

FIX defect

Answer 13

gives haemophilia B

X linked

Question 14

TF pathway inhibitor

Answer 14

suppresses the initiation of thrombin generation

expressed on healthy tissue

Question 15

antithrombin III

Answer 15

serine protease inhibitor
prevents diffusion of active coagulation enzymes
potentiated by heparins (when you give heparin there is no clotting)

Question 16

thrombomodulin

Answer 16

transmembrane protein (on endothelium)
receptor and cofactor for thrombin
makes thrombin recognise protein C and activate it

Question 17

protein C

Answer 17

pro-enzyme (serine protease)

vit. K dependant

Question 18

protein S

Answer 18

non-enzymatic cofactor for APC (activated protein c)
vit K dependant
deactivates coagulation

Question 19

FV leiden

Answer 19

gets activated by thrombin
SNP in exon 10
inactivation = different and less effective than normal FV
better cofactor, but can lead to DVT (gain of function)

Question 20

prothrombin G2021OA

Answer 20

mRNA mutation of prothrombin (more stable)

more prothrombin –> coagulation more active

Question 21

fibrinolysis

Answer 21

part of normal hemostasis
plasmin = key enzyme (created D-dimers)
high levels of D-dimer indicates thrombosis

Question 22

tPA dependant plasmin generation

Answer 22

tPA produced by endothelial cells
converts plasminogen to plasmin
fibrin = cofactor
tPA only active when bound to fibrin

Question 23

uPA dependant plasmin generation

Answer 23

uPA= pro-urokinase
uPA produced by endothelial cells, macrophages and epithelial cells
activated by plasmin
amplificates plasmin production
can occur in absence or presence of fibrin