Section 7 - Hemostasis Regulation Flashcards
1
Q
Protein C
- activation
- functions
A
- vitamin K dependent
- activated by thrombin-thrombomodulin complex
- inactivates FV and FVIII
- releases tPA
- protein S cofactor necessary for function
2
Q
Protein S
- forms
- function
A
- vitamin K dependent
- 60% bound to C4b, 40% free/active
- cofactor for protein C
-> inactivates VIIIa and Va
3
Q
Protein Z
- forms
- function
- bound to
A
- vitamin K dependent
- cofactor for ZPI
- degrades factor Xa
-> requires Ca and phospholipids
-> slow on its own, faster as cofactor
4
Q
Z related protease inhibitor
- function
- bound to
A
- vitamin K dependent
- cofactor for vitamin Z -> bound = more efficient
- degrades factor Xa (minor degradation of XIa w/o PZ)
5
Q
Antithrombin
- function
- drug associations
A
- irreversible complex with thrombin and Xa
- also irreversibly binds: 9-12 and plasmin
- heparin causes conformational change increasing inhibitory effect
6
Q
Where is heparin formed in the body
A
Mast cells and tissue basophils
7
Q
Where is Heparan (heparin like substance) formed in the body
A
Endothelial cells
8
Q
Heparin Cofactor II (HCII)
- production
- function
A
- formed in liver
- specific for thrombin neutralization
- accelerated function with heparin (less than AT+ heparin)
- regulates thrombin on PLT surface
9
Q
Tissue factor pathway inhibitor (TFPI)
- function
- secretion
A
- inhibits TFIII release = inhibits extrinsic pathway
- secreted by endothelial cells
10
Q
Endogenous plasminogen activators
A
- tPA
- urokinase
- XIIa and Kallikrein
11
Q
Functions of plasmin and specificity
A
- fibrinolysis and fibrinogenolysis
- most activity within the clot = fibrin major substrate for activity
- slightly inactivates Va and VIIa
- degrades XIIIa into inactive fragments
12
Q
define FDP and what it relates to
A
- primary fibrinolysis and secondary fibrinolysis
- fragments of fibrinogen/fibrin breakdown acting as coagulation inhibitors by attaching to fibrin monomer
- labeled: X, Y, D, E where D and E are end products
13
Q
describe the difference between fragments E and D in primary fibrinolysis
A
- fragment D is lysed with A and B fibrinopeptides on the end
- fragment E is the internal fibrinogen portion once fragment D is removed
14
Q
describe the sequence of events in secondary fibrinolysis
A
- same as primary except fragment D and E are missing fibrinopeptide A/B via thrombin action
15
Q
describe the formation of D-dimers
A
- stabilized fibrin polymers linked at the D domain
- when split by plasmin D domains remain bound together forming the D-Dimer
