Coagulation Testing Flashcards
What is hemostatsis the balance between?
- The bodies need to respond to injury by preventing hemorrhage by initiating thrombosis
- Maintaining effective circulation
What are the 3 components of hemostasis
- Vessel wall
- Platelets
- Coagulation system
What carries out primary hemostasis
Platelets
What are the components of primary hemostasis
- Adhesion of collagen to the site of vascular injury
- Adhesion of other platelets
- Release of platelet contents to promote platelet aggregation
- Provision of a phospholipid surface to assemble proteins of the coagulation cascade
What are examples of platelet contents?
- ADP
- ATP
- Calcium clotting factors
- Thromboxane A
Why is the phospholipid surface so important?
-Crucial for organizing and promoting interactions of clotting factors
What carries out secondary hemostasis?
The coagulation system
_______ circulate until they are activated
Proenzymes
What is the coagulation cascade divided into?
- Extrinsic
- Intrinsic
- Common
Are these cascades separate, or work in conjunction with each other?
Work in conjunction with eachother
Why are the pathways useful?
- Understanding in vitro lab tests
- Identifying specific factor deficiencies
Disruption of the endothelium results in the exposure of…
Tissue factor (thromboplastin) in subendothelial tissue
Exposure of tissue factor results in the ______ pathway
Extrinsic
How is the extrinsic pathway triggered?
Converting Factor 7 to 7a
The endothelial disruption also exposes ______ in the vascular wall
Collagen
The exposure of collagen results in the activation of ______________ in the _______ pathway
-Contact phase proteins in the intrinsic pathway
Contact phase enzymes are also called…
Proenzymes
T/F- Triggering of the extrinsic and intrinsic pathways occur simultaneously
True
What are the 2 activators of the coagulation cascade?
- Tissue Factor (extrinsic)
- Contact phase proteins (intrinsic)
What are 3 examples of contact phase proteins?
- High molecular weight kininogen
- Kallikrein
- Factor 12 (hagpan factor)
What are the 4 Vitamin K dependent factors?
2, 7, 9, 10
Where are vitamin K dependent factors formed?
Liver
What do factors 2, 7, 9, 10 require as a cofactor for optimal activity of the clotting cascade?
Vitamin K