V-Coagulation

Question 1

vascular system function

Answer 1

constriction of damaged vessels
healthy vessels will reduce unnecessary clot formation

Question 2

platelet system function

Answer 2

temporary platelet plug
primary hemostasis

Question 3

coagulation factor cascade function

Answer 3

make insoluble clot with fibrin
secondary hemostasis

Question 4

anticoagulation system function

Answer 4

inhibit coagulation

Question 5

fibrinolytic system function

Answer 5

degrade clots

Question 6

GPIb binds to

from platelet

Answer 6

vWF (von willebrand factor) from subendothelial matrix

for platelet adhesion

Question 7

GPVI binds to

from platelet

Answer 7

collagen from subendothelial matrix
for platelet adhesion

Question 8

protease activated receptor binds

Answer 8

thrombin to inc platelet activation and aggregation

Question 9

P2Y12 receptors bind

on platelets

Answer 9

ADP that gets released from platelet granules

for activation of nearby platelets and enhance plates already adhered

Question 10

TXA2 receptors bind

Answer 10

TXA2 secreted from platelets AFTER vWF and ADP bind

for platelet activation and enhance plates already adhered

same function as ADP/P2Y12

Question 11

GPIIb/IIIa bind

Answer 11

fibrinogen from plasma
for platelet aggregation

Question 12

function of NO and PGI2

Answer 12

released by healthy endothelium to inhibit platelet aggregation + act on smooth muscle to vasodilate

Question 13

how do platelets connect to coagulation cascade

Answer 13

activated platelets release pro-coagulant cofactors (Ca and neg charged phospholipids) to accelerate thrombin formation by coag cascade

Question 14

intrinsic pathway starts with

Answer 14

factor XII contacts collagen exposed by injury or phospholipids on platelets

Question 15

extrinsic pathway start with

Answer 15

factor VII contacts tissue factor exposed by injury

Question 16

intrinsic pathway steps

Answer 16

1. XII to XIIa
2. XI to XIa
3. IX to IXa
4. X to Xa (trace amounts)
5. prothrombin to thrombin in small amounts

Question 17

extrinsic pathway steps

Answer 17

1. tissue factor converts VII to VIIa
2. X to Xa (trace amounts)
3. prothrombin to thrombin in small amounts

Question 18

common pathway steps

Answer 18

1. Xa from both extrinsic and intrinsic convert prothrombin to thrombin in large amounts via complex with Va + phospholipids + Ca

Question 19

how coagulation gets amplified

Answer 19

the little amount of thrombin will activate
1. V to Va
2. VIII to VIIIa > will make complex with IXa to activate more Xa to be produced for the prothrombin complex

Question 20

thrombin affect on platelets

Answer 20

binds protease activated receptors on platelets to cleave fibrinogen to fibrin monomers > fibers > cross link via XIII activation

Question 21

cause of hemophilia A

Answer 21

factor VIII deficiency, x linked recessive
no complex is made with IXa to amplify Xa production for prothrombin complex

Question 22

cause of factor V leiden thrombophilia

Answer 22

mutation in factor V so prevents it from being inactivated by activated protein C (APC)
-aka always on so induces hypercoagulable state

Question 23

function of antithrombin

Answer 23

from the liver to bind heparan sulfate @ endo cells to degrade thrombin and Xa

Question 24

function of tissue factor pathway inhibitor

Answer 24

secreted from endo cells to reduce thrombin by inhibiting VIIa/TF complex and Xa

Question 25

function of thrombomodulin

Answer 25

on endo cells binds thrombin to activate APC
-APC and protein S complex will degrade Va and VIIIa

Question 26

tPA and uPA function

Answer 26

tissue plasminogen activator and urokinase plasminogen activator
-secreted by endo cells to convert plasminogen to plasmin so that plasmin can digest fibrin fibers/clots

plasmin is protease

Question 27

how fibrinolytic system is regulated

Answer 27

1. plasminogen activator inhibitor from platelets and endo cells so no degradation
2. a-2 plasmin inhibitor from liver so no degradation