Haemostasis

Question 1

are platelets and anticoagulation factors always present in blood vessels?

Answer 1

yes

Question 2

when do platelets and anticoagulation factors become activated ?

Answer 2

after damage or abnormal surface

Question 3

what are the three stages of vessel repair?

Answer 3

clot formation
clot remains confined to site of injury
clot breaks down

Question 4

what three things are involved in clot formation ?

Answer 4

platelets
vWF
coagulation factors

Question 5

what does vWF do?

Answer 5

von willebrand factor has receptors on its surface for collagen which is present in the sub endothelium and also to the activated platelets.
therefore this factor binds the collagen and activated platelets together to form a platelet plug

Question 6

what does vWF stand for?

Answer 6

von willebrand factor

Question 7

what is the function of the platelet plug?

Answer 7

it holds fibrogen in position

Question 8

what cleaves the fibrogen into fibrinopeptides ?

Answer 8

thrombin

Question 9

does fibrinogen have a positive or negative feedback on coagulation?

Answer 9

positive feedback

Question 10

what substance prevents more clots forming ?

Answer 10

natural anticoagulants

Question 11

name some natural anticoagulants?

Answer 11

TFPI (tissue factor pathway inhibitor)
anti thrombin
activated protein C and S

Question 12

what is the reaction which breaks down the clot?

Answer 12

fibrinolysis

Question 13

name two substances which are apart of the fibrinolytic system ?

Answer 13

t-PA

u-PA

Question 14

what is the function of the plasminogen activators ?

Answer 14

cleaves the plasmin from the plasminogen which degrades the fibrin clot

Question 15

what do the activated platelets release for clotting?

Answer 15

alpha and dense granules

Question 16

what do the dense granules contain?

Answer 16

ADP/ATP
calcium
serotonin

Question 17

what do the alpha granules contain?

Answer 17

vWF

thrombin

Question 18

what about the cell membrane is coagulation activation dependant on?

Answer 18

phospholipids

Question 19

what is the function of scramblase?

Answer 19

responsible for the translocation of phospholipids between the two monolayers of a lipid bilayer of a cell membrane

Question 20

state some medication which can affect anticoagulation?

Answer 20

aspirin 
clopidogrel 
ticagrelor 
warfarin 
heparins
rivaroxaban

Question 21

how is heparin administered ?

Answer 21

parentaly (injections)

Question 22

what does warfarin affect in the body

Answer 22

affects vitamin K and affects coagulation factors

Question 23

what affect does nitric oxide have on blood vessels?

Answer 23

relaxes vessels hence increases diameter and prevents platelet activation

Question 24

what affect does prostacyclin have on blood vessels?

Answer 24

relaxes vessels hence increases diameter and prevents platelet activation

Question 25

what enzyme does aspirin affect ?

Answer 25

COX