12-3 L1 Secondary Hemostasis Flashcards
1
Q
What hemostatic factor has the short-est half life
A
- Factor 7
2
Q
What is the mastor effector and regulator of the hemostatic cascade
- how does it up reg and down reg
A
Thrombin (2a)
- Up-regulates its own production
- Activatoin of 11,8,5
- down-regulates its own production
- activation of protein C (when associated with thrombomodulin)
3
Q
Name the 3 factors that are important for contact activation
A
- Prekallikrein (enzyme, activates 12)
- HMWK (high molecular wegiht kininogen, co-factor)
- Factor 12 (Enzyme activates factor 11)
4
Q
Factore 13
- what is it
- what activates it
- what does it do
A
- plasma transglutaminase
- activated by thrombin (F2)
- Cross-links fibrin monomers (covalaent bond b/t the glutamine to lysine residues of the gamma chain of fibrin)
5
Q
Vit K dependent factors
A
- F2,7,9,10 protein C & S
6
Q
What enzyme is effected by vit K def. and
what is role of the enzyme
A
-
Glutamyl carboxylase
- microsomal enzyme
- requires vit K as a cofactor
- converts glutamyl residues in the Gla domain (on precursoe proteins to gamma-carboxylglutamyl residues)
- Gla domain
- allows for Ca dependent binding of phospholipids
7
Q
What is important for maintaining the fibrinogen structure/stability?
A
- 3 Ca binding sites
- in addition to the requirement of Ca2+ binding by the vitamin K dependent factors
8
Q
coagulation factors
what is synthesized in the
- megakaryocyte
- endothelium
A
- megakaryocyte: vWF & V
- Endothelium: vWF and 8
9
Q
Inhibitors of coagulation
what are the 3 main points
A
- activation of fX by the TF/7a complex
- Activity of thrombin
- Cofactor activity of 8a and 5a
10
Q
define
TFPI (Tissue factor pathway inihibitor)
A
- Inhibits the extrinsic pathway of coagulation by binding to the complex of TF, 7a and 10a
11
Q
Thrombomodulin
- decreases activity for what
- Increases activity for what
A
- decreases
- F5,8,11
- Fibrinogen
- PARs
- Increases
- Protein C
- TAFI (thrombin activatable fibrinolysis inhibitor
12
Q
Thrombin-thrombomodulin complex activates what?
what is the cofactor of the protein it activates?
A
- protein C
- Protein S
13
Q
Antithrombin
- inhibits what
- AT activity increased by what?
A
- inihibits: FXa and F2
- greatly increased by heparins
14
Q
Fibrinolysis
is the degradation of fibrin by plasmin
- degradation occurs where?
- give 2 exmaples of PA (plasminogen activators)
A
- lysine-arginine bonds
- tPA (tissue plasminogen activator)
- uPA (urokinase-type plasminogen activator
15
Q
What inhibits fibrinolysis
(name 3 things and their action)
A
- alpha2-antiplasmin: directly inhibts plasmin
- PAI-1 (plasminogen activator inhibitor): directly inhibits plasminogen activators
- thrombin/thrombomodulin activation of TAFI
