Study Guide: Chapter 14 Flashcards
To stop bleeding by activating the coagulation system
hemostasis
When do you need hemostasis?
To stop bleeding within a few minutes by forming a clot at the injury site.
What are the 5 important factors involved in hemostasis?
1) Small blood vessel integrity
2) Enough platelets
3) Normal amounts of coagulation factors
4) Normal amounts of coagulation inhibitors.
5) Sufficient calcium
Which phase I coagulation factor is linked to hemophilia A?
factor VIII
Which phase 1 coagulation factor is linked to hemophilia B?
factor IX
Which phase I coagulation factor is linked with the Leiden mutation?
factor V
What are antithrombin and protein C?
Coagulation inhibitors
Which coagulation inhibitor inhibits thrombin?
Antithrombin
Which coagulation inhibitor inhibits factor V (Leiden) and VIII (hemophilia)?
protein C
What is another name for fibrinolysin?
plasmin
What plasminogen activator functions as the central coordinator of both coagulation and fibrinolysin processes?
Thrombin
Which plasminogen activators can be used clinically to in heart attack patients to dissolve a clot?
tPA and streptokinase
Why would it be preferable, if possible, to give a patient anticoagulants than plasminogen activators?
PAs could cause serious bleeding (e.g., stroke)
What is the difference between plasminogen activators and anticoagulants?
PAs dissolve fibrin clots; anticoagulants prevent further clotting and let the body’s own fibrinolysin dissolve the clot.
When would you give a plasminogen activator to a patient?
In an emergency if a clot needs to be dissolved immediately.
Which phase 1 pathway is most important in initiating clotting?
Extrinsic pathway
Enzyme needed to produce thrombin in phase II of the coagulation process.
thromboplastin
What does prothrombinase (activated thromboplastin) do?
Converts prothrombin to thrombin
What is used to convert fibrinogen to fibrin?
thrombin
What is the most common clotting disorder?
Thrombocytopenia
Too few platelets
thrombocytopenia
What is the most common bleeding disorder?
von Willebrand’s Disease
What causes vWD?
vWF deficiency
True or false: Phase I coagulation disorders are all hereditary.
True
Classic anticoagulant that acts rapidly/immediately to bind and enhance antithrombin III
(a natural coagulation inhibitor) activity thereby inhibiting thrombin activity, its production, and the coagulation cascade
Heparin
Classic anticoagulant that provides longer term (than heparin) inhibition of all the vitamin K dependent cofactors.
Coumadin (Warfarin)
Two examples of newer medications that directly inhibit thrombin activity.
1) Pradaxa
2) Argatroban
Two examples of newer anticoagulant medications that inhibit prothrombinase (and therefore thrombin production)
1) Xarelto
2) Eliquis
What causes unwanted release of thromboplastic substances into the circulation to (over)stimulate coagulation, including disseminated intravascular coagulation (DIC)?
1) Shock
2) Widespread infections
3) Tissue necrosis
What condition is characterized by major hemorrhaging caused by thromboplastic substances being disseminated into the circulation, causing the body to quickly use up its coagulation factors and a surge in clot lysis?
Disseminated intravascular coagulation (DIC)
What happens in patients in with thromboplastic materials are slowly released, providing enough time for them to be replaced? What types of patients does this occur in?
Net overall clotting throughout the body; advanced cancer
