The Extrinsic Pathway operates on the initiating cell
What is the role of the Extrinsic Pathway?
Formation of the fibrin plug
Activation of Factor V
The Intrinsic Pathway works on...
The vW factor
The platelet surface
The Intrinsic pathway is designed to generate thrombin bursts
Name the three steps of Coagulation
What begins the Initiation phase?
Vascular injury initiates trigger factor
Vascular injury exposes collagen for platelets to bind
Vascular injury causes blood cells to lyse
Trigger factor activates VII, which activates smal amounts of
X & XI bind to platelets and produce small amounts of Thrombulin
Thrombin initiates Amplification
The platelets act as a surface for the assembly of what factor complexes?
IX & VIII
Prethrombinase (X & V)
What happens in Propogation
Activated platelets/complexes generate Thrombin Burst
Activated platelets/complexes generate Thrombulin Burst
Activated platelets/complexes generate Thromblin Burst
What two things are required for Fibrin Clot formation?
Fibrinogen --> Fibrin
Thrombin production is the crucial step in haemostasis
The first step in Coagulation Disorder diagnosis is a family & drug history
Name the two main clinical presentation of coagulation disorders
Bleeding in deep tissues
Bleeding in joints
Easy cutting of skin
Prethrombin Time is anassessment of the _ Pathway
Prethrombin time is expressed as an international, normalised ratio
Activated Partial Thromboplastin Time is an indicator of...
Which of the following are not Coagulation Disorder investigations?
Thrombin Clotting Time
Fibin Clotting Time
How do you evaluate increased prethrombin time?
Mix with normal platelets (50:50)
Remove half the platelets from a sample
Then a Factor VII assay
How do you evaluate Activated Partial Thromboplastin Time (APPT)?
Mix with normal plasma
Then do a Factor VIII, IX, XI assay
Then a FXII assay
Lack o Factor X causes no symptoms
Factor I assay is used if bot PT and APTT is elevated
If both PT and APTT is normal, what is tested for?
Aquired Coagulation Deficiencies are caused by a lack of what?
What can cause Aquired Vit K deficiency?
Massive Transfusion Effect
Vit-K deficiency can be drug induced i.e. in the case of liver disease
Haemophilia A is caused by what?
Factor VIII deficiency
Factor VI deficiency
Factor V deficiency
Haemophilia A is sex linked
Haemophilia B is a Factor IX deficiency
The mutations for Haemophilia A & B are found on which chromosome?
How do you identify Haemophilia B?
Factor IX assay
Von Willebrands disease is caused by a lack of factor
vW disease is detected by
Since many things can effect the levels of vWF, testing is difficult
vW disease can be qualitative or quantitative