Case 8

Question 1

What are the four main stages of haemostasis?

Answer 1

Vascular spasm
Platelet plug formation
Coagulation
Fibrinolysis

Question 2

What are the contents of platelet alpha granules?

Answer 2

VWF
clotting factors
PDGF

Question 3

What are the contents of platelet dense granules?

Answer 3

ADP
ATP
Serotonin
Ca2+

Question 4

GP1a facilitates interaction between…

Answer 4

Platelets and collagen (adhesion)

Question 5

GP1b facilitates interaction between…

Answer 5

Platelets and VWF

Question 6

GP2b and GP3a facilitate interactions between…

Answer 6

Platelets and platelets (aggregation)

Question 7

What are the four stages of platelet plug formation?

Answer 7

Adhesion
Aggregation
Release reaction
Platelet activation

Question 8

What is the effect of NO on platelets?

Answer 8

NO is an inhibitor of platelet activation

Question 9

What are the 3 stages of coagulation?

Answer 9

Initiation
Amplification
Propagation

Question 10

What is the eventual end product of coagulation?

Answer 10

Production of thrombin

Question 11

What is the function of thrombin?

Answer 11

Converts fibrinogen to fibrin

Fibrin forms a stable mesh around platelet plug

Question 12

What are the components of the extrinsic tenase complex?

Answer 12

F10, F7a, tissue factor

Question 13

What are the components of the intrinsic tenase complex?

Answer 13

F10, F9a, F8a

Question 14

What are the components of the prothrombinase complex?

Answer 14

F10a, F5a

Question 15

What is the biggest trigger for the coagulation cascade?

Answer 15

Membrane bound tissue factor

Question 16

Which tenase complex is responsible for 90% of thrombin production?

Answer 16

Intrinsic tenase

Question 17

What is the contact pathway?

Answer 17

An aspect of coagulation the results in the eventual production of F9a from F12, kininogen and pre-kallikrenin

PATHWAY IS SEEN IN VITRO BUT NOT IMPORTANT IN VIVO

Question 18

What factor stabilises the fibrin mesh around the platelet plug?

Answer 18

F13a

Question 19

Name the 4 factors that are vitamin K dependent…

Answer 19

F2
F7
F9
F10

Question 20

How does smoking effect thrombosis?

Answer 20

Decreases NO and prostacyclin production
Increases endothelin synthesis

NET IMPACT IS PROMOTION OF CLOTTING

Question 21

What is factor 5 leiden?

Answer 21

Autosomal inheritance of a mutant protein

Inhibits protein C binding to factor 5a, meaning there is decreased regulation of clotting process

Question 22

How is the location of thrombus formation related to severity of disease?

Answer 22

Distal thrombus less severe than proximal thrombus

Question 23

What are the two hemodynamic consequences of pulmonary embolism?

Answer 23

RV afterload increases causing R side heart failure

LV functionality impacted if IV septum bows in response to increased pressure

Question 24

What does prothrombin time measure?

Answer 24

Time taken for prothrombin –> thrombin

A measure of vitamin K dependent clotting pathways

Question 25

What does INR measure?

Answer 25

A standardised form of prothrombin time

Question 26

What does activated partial thromboplastin time measure?

Answer 26

Measures the intrinsic clotting pathway

Question 27

What does the D-dimer test measure?

Answer 27

Presence of FDPs

Question 28

What does thrombin time measure?

Answer 28

Time taken for fibrinogen --> fibrin