Coagulation

Question 1

1. There is a balance between which two processes to allow rapid coagulation when necessary, and to prevent coagulation when it is inappropriate?
2. In what common location are heparan sulfate glycoproteins, prostacyclin (PGI2), thrombomodulin, and tissue plasminogen activator found?
   What function do they share?

Answer 1

1. pro-coagulation and anti-coagulation
2. Endothelial cell surface
   anti-coagulation

Question 2

1. Generally, how do platelets promote coagulation?

Answer 2

1. platelets form a physical plug and contain numerous factors which promote coagulation

Question 3

1. Where are clotting factors found?
2. What is the ultimate product of coagulation?

Answer 3

1. Found in plasma, tissue, and platelets
2. Ultimate product - hard fibrin clot

Question 4

1. What is pro-coagulation?
2. What is anti-coagulation?
3. What is fibrinolysis?

Answer 4

1. factors and processes which promote coagulation
2. factors and processes which inhibit coagulation
3. factors and processes which promote dissolution of the clot

Question 5

1. Which of the following factors require vitamin K:
   Fibrinogen, prothrombin, tissue factor, Ca2+, proaccelerin, Proconvertin, antihemophilic factor, christmas factor, stuart factor, plasma thromboplastin antedcedant, hageman factor, fibrin stabilizing factor, prekallikrein

Answer 5

1. Prothrombin, Proconvertin, Christmas factor, and Stuart factor
   (AKA prothrombin, FVII, FVIX, FX, protein C and protein S)

Question 6

1. Draw the extrinsic pathway and indicate which parts are activatable/inhibitable and what factor is responsible for the activation/inhibition

Question 7

1. What facilitates FX -> FXa?
2. FXa goes on to form a complex with ____ on the ____ membrane
3. ______ also binds to the membrane. What is needed for this to happen? What does FXa do to this factor?

Answer 7

1. VIIa/TF/Ca complex
2. FXa forms a complex with FVa on the platelet membrane
3. Prothrombin also binds to the membrane. This is Ca2+ dependent.
   FXa proteolytically activates prothrombin to thrombin

Question 8

1. What does thrombin do to fibrinogen?
2. Thrombin promotes further coagulation by activating factors in the intrinsic, common final, and extrinsic pathways. Which factors does it activate in each pathway?

Answer 8

1. Thrombin proteolytically converts fibrinogen to fibrin
2. Intrinsic - FVIII and FXI
   Common Final - FV and FXIII
   Extrinxic - FVII

Question 9

1. Draw the intrinsic pathway and indicate which parts are activatable/inhibitable and what factor is responsible for the activation/inhibition

Question 10

1. Draw the common final pathway and indicate which parts are activatable/inhibitable and what factor is responsible for the activation/inhibition

Question 11

Draw the intrinsic, extrinsic, and common final pathways, and show how they fit together