L04: Haemostasis

Question 1

What are platelets involved in

Answer 1

Clotting blood cells

Question 2

What are the 3 types of granules in platelets

Answer 2

Alpha
Dense
Glycogen

Question 3

What do alpha granules contain and release

Answer 3

F5
F8
Fibrinogen
VWF

Question 4

What do dense granules contain

Answer 4

ADP

Serotonin

Question 5

What do glycogen granules contain

Answer 5

Energy source for platelets

Question 6

What is the first reaction of the blood vessels when there is damage

Answer 6

Vasoconstriction

Question 7

What does vasoconstriction do to the blood flow

Answer 7

Decrease it

Question 8

What happens to VWF

Answer 8

Binds to exposed collagen in the damaged vessel

Question 9

When VWF binds to collagen where else does it bind to

Answer 9

GP1B receptors on the platelet

Question 10

What happens to the GP1B platelet when VWF binds

Answer 10

It upregulates to GP2B receptors

Question 11

When there are GP2B receptors what binds to it

Answer 11

More VWF

Or fibrinogen

Question 12

What does GP2B cause

Answer 12

Cross linking of many platelets together

Question 13

How are the granules in the platelet become activated to release their substances when the platelet it activated

Answer 13

ADP from damaged blood vessels cause degranulation of the granules

Question 14

Which granules are degranulated

Answer 14

Dense

Alpha

Question 15

When the platelets have stuck to the damaged blood vessel what is the next thing that occurs

Answer 15

Coagulation cascade

Question 16

How many pathways does the coagulation cascade involve

Answer 16

3

Question 17

What are the pathways of the coagulation cascade

Answer 17

Intrinsic
Extrinsic
Common pathway

Question 18

What is the outcome of the extrinsic and intrinsic pathway

Answer 18

To give F10a that is in the common pathway

Question 19

What happens in the extrinsic pathway

Answer 19

1) Factor 7 is converted to F7A by F3 (tissue factor)

2) Factor 7A converts F10 to F10A

Question 20

What happens in the intrinsic pathway

Answer 20

1) factor 12 is converted to F12A when it touches the platelet
2) F12A converts F11 to F11A
3) F11A converts F9 to F9A
4) F9A reacts with F8 and calcium to convert F10 to F10A

Question 21

What happens in the common pathway

Answer 21

1) F10a reacts with F5 to convert prothrombin to thrombin

2) thrombin converts fibrinogen to fibrin

Question 22

Is fibrin insoluble are soluble

Answer 22

Insoluble

Question 23

What is Bernard soulier syndrome due to

Answer 23

Deficiency in GP1B receptor

Question 24

What is glanzmann’s thrombasthenia due to

Answer 24

Deficiency of GP2B receptor

Question 25

What is haemophilia A due to

Answer 25

Deficiency in F8

Question 26

What is haemophilia B due to

Answer 26

Deficiency in F9

Question 27

What is con willebran disease due to

Answer 27

Deficiency of VWF

Question 28

What are the 3 ways of breaking down a clot

Answer 28

Fibrinolysis i.e with thrombin Protein c/s system Antithrombin

Question 29

Describe fibrinolysis

Answer 29

1) thrombin releases TPA 2) TPA binds to fibrin in the clot 3) circulating plasminogen binds to TPA 4) plasminogen is converted to plasmin 5) plasmin degrade the clot by breaking down the fibrin

Question 30

Describe the protein C/S system

Answer 30

1) thrombin binds to thrombomodulin on the vessel endothelial cells 2) Protein c then binds to thrombin which is on the thrombomodulin 3) protein c becomes activated 4) activated protein c binds to protein s 5) protein c/s inactivates active F8,5 (Intrinsic pathway) 5) coagulation pathway stops

Question 31

Describe the antithrombin

Answer 31

Anti thrombin inactivates activate F11,10,9

Question 32

What test do we use to look at the function of the coagulation cascade

Answer 32

Coagualtion test

Question 33

What does the coagulation test involve

Answer 33

PT | APTT

Question 34

What does the coagulation test measure

Answer 34

Time in the intrinsic and extrinsic pathway

Question 35

What pathway does the PT test look at

Answer 35

Extrinsic pathway

Question 36

What pathway does the APTT look at

Answer 36

Intrinsic pathway

Question 37

Usually which test is not longer

Answer 37

PT

Question 38

Why is the PT test not long i.e the extrinsic pathway

Answer 38

It involves less factors so is quicker

Question 39

What does a prolonged PT suggest

Answer 39

Deficiency in the factors involved in the extrinsic pathway : F7

Question 40

What does a prolonged APTT indicate

Answer 40

``` Deficiency in the factors involved in the intrinsic pathway: F12 F11 F9 F8 ```

Question 41

What does prolonged both PT and APTT indicate

Answer 41

Deficiency in the common pathway: F5 F10 Fibrinogen