Week 5 Flashcards
What are the 3 component of the haemostatic system that help prevent blood loss?
Blood vessels, platelets, Plasma Proteins :blood clotting
What is considered Primary haemostasis?
Blood vessels & Platelets
What is considered Secondary haemostasis?
Platelets & Plasma Proteins
What does haemostasis mean?
the process to prevent and stop bleeding
What are the 3 functions of platelets?
Adhesion (reversible), Aggregation (irreversible), Secretion (irreversible)
Which factor is activated by both intrinsic and extrinsic pathways?
X marks the spot
Which factor acts as a co-factor with FX?
Factor V (V fits into X)
Which factors are in the common pathway?
FII and FI
Which factor(s) are in the extrinsic pathway?
FVII
Which factor(s) are in the intrinsic pathway?
FXII, XI, IX, VIII (TENET)
Which factor crosslinks fibrin?
FXIII
Intrinsic pathway is measured by what test
APTT
Extrinsic pathways is measured by what test
PT
What does APTT and PT stand for?
APTT - Activated partial thromboplastin time.
PT - Prothrombin Time
It is called an intrinsic pathway because …
FXII is found IN blood
It is called an extrinsic pathway because……
Tissue factor is not found in blood
What is normally contained in a clot-base pro-coagulant screen? (5)
PT, APTT, thrombin clotting time (TCT), Fibrinogen Assay (FIB), platelet count
Which test monitors for warfarin and which one for heparin?
Warfarin - PT
Heparin - APTT
The PT test is most sensitive to levels of what factor?
FVII
What is International Normalised Ratio (INR)?
a calculation based on results of a PT. Used to monitor warfarin.
In the APTT test a Reagent contains ________ that
activates Factor _______ which then Initiates an _______ cascade
phospholipid, FXII, intrinsic
A PT test consists of what 3 things?
PPP + PT reagent + Ca++
Which factor gets activated in a PT test?
FVII
An APTT test is prolonged with <30% normal activity of what 3 factors?
- FVIII
- FIX
- FXI
In a TCT test Bovine thrombin reagent cleaves
________ to form ______ polymer
fibrinogen, fibrin
A prolonged TCT test occurs in the presence of what 3 things?
- Low fibrinogen
- Heparin
- FDPs
What are the 3 principal regulators of the coagulation regulatory system?
i. Tissue factor pathway inhibitor (TFPI)
ii. Protein C pathway
iii. Antithrombin (AT)
TFPI only functional if which factor is activated
X