Section 7: Regulation and Fibrinolysis Flashcards
1
Q
Protein C is made where and dependent on what?
A
- Made in liver
- Vit K dependent
2
Q
How is Protein C activated?
A
Thrombin-thrombomodulin complex attached to endothelium can activate Protein C
3
Q
Protein C functions
A
- inactivate Va and VIIIa
- liberates tPA from endothelial cells
- Protein S is a cofactor
4
Q
Protein S traits
A
- Vit K dependent
- Made in liver
- Non-proteolytic
5
Q
Forms of Protein S
A
- 60% bound to C4b binding protein (complement protein)
- 40% free (this is the active form in coag)
6
Q
Protein S function
A
Cofactor to Protein C
7
Q
Protein Z traits
A
- Vit K dependent
- Made in liver
- Similar structure to other vit K dep factors except no activation site and non-proteolytic
8
Q
Protein Z functions
A
- cofactor to Protein Z-Related Protease Inhibitor (ZPI)
- major role is to degrade Factor Xa
- need calcium + phospholipids
- slow-acting on its own
9
Q
Protein Z-Related Protease Inhibitor (ZPI) traits
A
- vit K dep
- made in liver
10
Q
ZPI functions
A
- cofactor to Protein Z
- action accelerated 1000-fold in presence of Protein Z
- major role is to degrade Factor Xa
- also degrades Factor XIa on its own
11
Q
Antithrombin (AT, formerly ATIII) location made and function
A
- made in liver
- functions to form irreversible complex with Factors IIa, IXa, Xa, XIa, XIIa, and plasmin to slowly inactivate/neutralize them
12
Q
Where is heparin found in the body?
A
Mast cells and tissue basophils
13
Q
Heparin-like substances made by ___
A
Endothelial cells
14
Q
Heparin cofactor II (HC-II) trait and functions
A
- made in liver
- function is specific to IIa neutralization/inactivation
- HC-II has accelerated activity in presence of heparin but less than AT
- present in platelets and may play role in thrombin regulation generated on plt surface
15
Q
Tissue Factor Pathway Inhibitor (TFPI) functions
A
- low conc extrinsic pathway inhibitor
- ECs secrete TFPI into plasma
- TFPI inhibits Tissue Factor/Factor VIIA complex