Coagulation 3 Flashcards
What is the FIRST coagulation factor activated in the extrinsic pathway?
a. fibrinogen
b. Stuart-Prower factor
c. Tissue factor
d. labile factor
c. tissue factor
The extrinsic pathway is activated by
vascular injury or when the vessel wall comes into contact with blood
The extrinsic pathway includes factors
3 & 7
The extrinsic pathway is _______________- than the intrinsic pathway
faster
The extrinsic pathway is measured by the
PT & INR
The extrinsic pathway is inhibited by
warfarin
_____________ activates the extrinsic pathway
Tissue factor
Tissue factor activates factor
7
Factor 7 activates _ in the presence of _
10; 4 (Ca+)
What is the mnemonic for the extrinsic pathway?
For 37 cents, you can purchase the extrinsic pathway
What factor will be the first factor to become deficient in patients with liver failure, vitamin K deficiency, and those on warfarin?
factor 7 (has the shortest half-life)
How fast can a clot form via the extrinsic pathway of the coagulation cascade?
~15 seconds
What factors are specific to the classical intrinsic pathway? (select 3)
a. 4
b. 6
c. 7
d. 8
e. 9
f. 11
8, 9 & 11
The intrinsic pathway is activated by
blood trauma
The intrinsic pathway includes factors
12, 11, 9 & 8
The intrinsic pathway is _______ than the extrinsic pathway
slower
The intrinsic pathway is measured by
PTT & ACT
The intrinsic pathway is inhibited by
heparin
The classical intrinsic pathway is also called the
contact activation pathway
What is the mnemonic for the intrinsic pathway?
If you can’t buy the intrinsic pathway for $12, you can buy it for $11.98
What factor is missing with hemophilia A?
factor 8
______ are missing with thrombocytopenia
Platelets
What are the five steps of the intrinsic pathway?
- blood trauma exposure to collagen–> activates factor 12
- factor 11 activation
- factor 9 activation
- factor 10 activation (via factor 9a & 8)
- Prothrombin activator activates thrombin (factor 2a)
How long does it take to form a clot via the intrinsic pathway of the coagulation cascade?
~6 minutes
What factors make up the intrinsic pathway?
12, 11, 9, & 8
Place the events of the final common pathway in the correct sequence:
thrombin activates fibrin monomer
prothrombin activator activates thrombin
activated fibrin stabilizing factor crosslinks fibrin
1st. Prothrombin activator activates thrombin
2nd. Activated fibrin stabilizing factor crosslinks fibrin
3rd. Thrombin activates fibrin monomer
The primary goal of both the intrinsic and extrinsic pathways are to
produce prothrombin activator
The final common pathway begins where
prothrombin activator changes prothrombin (2) to thrombin (2a)
Thrombin (2a) is a proteolytic enzyme that changes
fibrinogen to fibrinogen monomer
After the platelets aggregate, _______ is incorporated into the platelet plug
fibrin
The clot will stay in place until the
underlying vascular tissue has repaired itself
Prothrombinase is a complex of
complex of 10a + 5a + 4
What is the mnemonic for the final common pathway?
The final common pathway can be purchased at the five and dime for 1 or 2 dollars on the 13th of the month.
What is the role of thrombin?
it converts fibrinogen to fibrinogen monomer
What must be present to convert fibrinogen monomer to fibrin fibers?
Calcium (factor 4)
Identify the true statements regarding fibrinolysis. (select 2)
a. D-dimer measures fibrin split products
b. plasminogen is synthesized in the endothelium
c. tPA inhibitor inhibits the conversion of fibrinogen to fibrin
d. alpha-2 antiplasmin inhibits the action of plasmin on fibrin
a. D-dimer measures fibrin split products
d. alpha-2 antiplasmin inhibits the action of plasmin on fibrin
Since the clot is only a temporary fix while the vessel repairs itself, the body needs a way to breakdown the clot after it is no longer needed. This process is called
fibrinolysis
________ is a proteolytic enzyme that degrades fibrin into fibrin degradation products
Plasmin
Plasminogen is incorporated into the clot as it’s being formed, but it lays dormant until a
plasmin activator activates it (e.g. tPA, urokinase)
The body has a mechanism to stop the clot from increasing indefinitely. These processes include:
vasodilation & washout of ADP & TxA2
tissue factor pathway inhibitor neutralizes tissue factor
protein C & S, inhibiting factors 5a & 8a
antithrombin inactivates thrombin (2a) as well as factors 9a, 10a, 11a, and 12a
Fibrin degradation products are measured by
D-dimer
Plasmin activation is the result of:
injured tissue releasing tissue plasminogen activator (tPA) (major)
urokinase produced by the kidneys and released into the circulation (minor)
Plasmin activators are used therapeutically to
dissolve thrombi and restore blood flow
Once the clot is degraded, the body needs a way to turn off the fibrinolytic process:
tPA inhibitor (TPAI) inhibits the conversion of plasminogen to plasmin
Alpha-2 antiplasmin inhibits the action of plasmin on fibrin
What 2 enzyme inhibitors turn-off the fibrinolytic process?
tPA inhibitor (TPAI)
alpha-2 antiplasmin
