Term
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Definition
| The stoppage of blood flow |
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Term
| What are the two main categories that disorders of hemostasis? |
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Definition
The inappropriate formation of clots within the vasculature system (thrombosis)
The failure of blood to clot in response to an appropriate stimulus (bleeding) |
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Term
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Definition
| Plasma proteins present as inactive procoagulation factors that performs a specific step in the coagulation process. |
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Term
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Definition
| Natural process that keeps naturally occurring blood clots from growing and causing problems. |
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Term
| Circulating Anticoagulant |
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Definition
| A substance in the blood that inhibits normal blood clotting and may cause a hemorrhagic syndrome. |
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Term
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Definition
| A laboratory test used to measure the time necessary to generate fibrin after activation of factor VII. Measures extrinsic and common pathways (factors VII, V, X, prothrombin and fibrinogen) |
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Term
| Activated Partial Thromboplastin Time (aPTT) |
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Definition
| A laboratory test that measures the time necessary to generate fibrin from initiation of the intrinsic pathway. |
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Term
| When is the aPTT abnormal? |
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Definition
| Abnormal with decreased quantities of factors of the intrinsic and common pathways. Prolonged if a patient has less than approx. 30% of normal activity. |
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Term
| What is the normal reference range for prothrombin time? |
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Definition
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Term
| What is the normal reference range for activated partial thromboplastin time? |
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Definition
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Term
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Definition
| Time of the reaction of fibrinogen to fibrin in the presence of thrombin |
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Term
| What is the normal reference range for thrombin time? |
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Definition
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Term
| What does it indicate if clot formation is prolonged? |
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Definition
| It indicates either a quantitative or qualitative fibrinogen defect. |
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Term
| What is another name for factor IX? |
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Definition
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Term
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Definition
| Serine protease of the coagulation cascade involved in the intrinsic pathway. Factor IX mediates the conversion of factor X to factor Xa |
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Term
| Deficiencies of factor IX result in what? |
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Definition
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Term
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Definition
| Glycoprotein that is necessary for platelet adhesion.Circulates in the blood as a carrier protein for coagulation factor VIII. |
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Term
| Adhesion to what surface occurs when the platelet membrane receptor binds to vonWillebrand factor? |
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Definition
| Vessel subendothelial layer |
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Term
| Adhesion to the vessel subendothelial layer connects the platelets to exposed... |
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Definition
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Term
| The binding of ADP to the platelet membrane induces a conformation change of what receptors? |
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Definition
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Term
| A confirmation change of the gpIIb/IIIa receptors on the platelet membrane allows them to bind to what? |
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Definition
| Fibrinogen and form aggregates. |
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Term
| What are the five stages of homeostasis? |
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Definition
1. Vessel spasm
2. Formation of the platelet plug
3. Blood coagulation
4. Clot retraction
5. Clot dissolution |
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Term
| Besides ADP, platelets secrete the prostaglandin TXA2 which is an important stimulus for what? |
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Definition
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Term
| What leads to the primary hemostatic platelet plug? |
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Definition
| The combined actions of ADP and TXA2 lead to the expansion of the enlarging platelet aggregate, the primary hemostatic platelet plug |
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Term
| Conversion of the primary platelet plug into a definitive clot (known as the secondary hemostatic platelet plug) occurs when? |
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Definition
| It occurs as the coagulation pathway is activated on the surface of the aggregated platelets and fibrinogen is converted to fibrin, thereby creating a fibrin meshwork that cements the platelets and other blood components together. |
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Term
| When is activated partial thromboplastin time prolonged? |
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Definition
| It is prolonged if a patient has less than approx 30% normal activity |
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Term
| What factors make up the intrinsic pathway? |
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Definition
| Factors XII, XI, IX VII, X, V, II and fibrinogen |
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Term
| What factors make up the extrinsic pathway? |
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Definition
| Factors VII, X, II V and firbrinogen |
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Term
| What factors make up the common pathway? |
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Definition
| Factors X, prothrombin, thrombin, fibrinogen and fibrin |
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Term
| The main pathway for the initiation of the coagulation cascade is the? |
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Definition
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Term
| The intrinsic pathway acts to do what? |
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Definition
| Amplify the coagulation cascade |
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Term
| Hemophilia B is caused by what? |
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Definition
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Term
| To test for hemophilia B the laboratory tests focus on Factor IX concentrates. What are the PT and aPTT times for patients who have hemophilia B? |
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Definition
PT is normal
aPTT is prolonged |
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Term
| Hemophilia C is caused by what? |
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Definition
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Term
| To test for hemophilia C, the laboratory tests focus on Factor XI levels. What are the PT and aPTT times for a patient with hemophilia C? |
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Definition
PT is normal
aPTT is prolonged |
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Term
| Hemophilia A is caused by what? |
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Definition
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Term
| What is the order of incidence for hemophilia? |
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Definition
| Hemophilia A > Hemophilia B > Hemophilia C |
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Term
| To test for Hemophilia A, the laboratory tests focus on factor VIII levels. What are the PT and apTT times for patients with hemophilia A? |
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Definition
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Term
| Hemophilia A is monitored and treated via measuring the % activity of Factor VIII. What are the % activity levels? |
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Definition
<1%= severe
1-5%= moderate
5-20%= mild |
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Term
| What are usual methods of treatment for Hemophilia A? |
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Definition
Recombinant Factor VIII
DDAVP (desmopressin)
Plasma concentrate |
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Term
| Hemophilia A involves what type of bleeding? |
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Definition
| Anatomic bleeding with deep muscle and joint involvement. (Bleeding into CNS, GI tract and kidneys) |
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Term
| Hemophilia B involves what? |
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Definition
|
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Term
| Hemophilia C involves what? |
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Definition
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Term
| Hemophilia A has what type of inheritance pattern? |
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Definition
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Term
| Hemophilia B has what type of inheritance pattern? |
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Definition
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Term
| Hemophilia C has what type of inheritance pattern? |
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Definition
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Term
| Disseminated Intravascular Coagulation (DIC) |
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Definition
| Decreased platelet count. (Also involves abnormal PT, fibrinogen and platelet count) |
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Term
| What are the laboratory values for DIC? |
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Definition
PT is prolonged
aPTT is prolonged
D-Dimer is increased |
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Term
| What does treatment of DIC involve? |
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Definition
Elimination of the primary condition
DIC with bleeding requires replacement therapy
DIC with thromboemboli requires heparin |
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Term
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Definition
| Affects the synthesis of vWF |
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Term
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Definition
| Quantitative and also the most common type of vWF |
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Term
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Definition
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Term
| What are some clinical symptoms of vWF? |
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Definition
Mild to moderate mucocutaneous bleeding
Secondary to trauma or surgery
Life-threatening hemorrhage |
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Term
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Definition
| Severe deficiecy (Factor 8 decreased because it breaks down) |
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Term
| What are common treatments of vWF disease? |
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Definition
| DDAVP (desamino 8 D arginine vasopressin) stimulates the release of vWF from endothelial cells |
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Term
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Definition
| Large plaelet disease. Mutation in the genes that code for GP Ib and GP IX |
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Term
| What is the pathophysiology of Bernard-Soulier Syndrome? |
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Definition
| Qualitative defect in GP Ib/IX complex |
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Term
| What are symptoms of Bernard-Soulier Syndrome? |
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Definition
| Manifested in infancy or childhood. Involves severe bleeding, purpura, epistasis, gingival bleeding, menorhhagia, postraumatic and postoperative bleeding |
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Term
| What are the laboratory values for Bernard-Soulier Syndrome? |
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Definition
Bleeding time is prolonged (20 minutes)
Platelet count is decreased (50,000-80,000/uL)
Giant platelets
Platelet aggregation |
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Term
| What does treatment for Bernard-Soulier Syndrome involve? |
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Definition
Platelet transfusions
DDAVP
Recombinant facotr VIIa |
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Term
| Platelets do not bind directly to what? |
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Definition
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Term
| What is the pathophysiology of Glanzmann's Thrombasthemia? |
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Definition
| Qualitative defect in GP IIb/IIIa |
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Term
| What are clinical symptoms of Glanzmann's Thrombasthemia? |
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Definition
Appeas in infancy or childhood
Severe and debilitating bleeding episodes |
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Term
| What are the laboratory values for Glanzmann's Thrombasthemia? |
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Definition
Normal platelet count and morphology
Prolonged bleeding time
Platelet aggregation |
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Term
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Definition
| A prescription drug that acts as an anticoagulant, preventing platelets from forming a blood clot |
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Term
| What is Heparin's mechanism of action? |
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Definition
| Heparin binds to enzyme inhibitor antithrombin III causing a conformational change that results in its acitvation through an increase of the flexibility of its reactive loop. The activated AT inactivates thrombin and other proteases involved in blood clotting including Facor Xa. The inactivation of these factors prevents the formation of fibrin, preventing a blood clot from being formed. |
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Term
| Antithrombin (antithrombin III) |
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Definition
| A glycoprotein that inactivates several enzymes of the coagulation system. Its activity is increased by heparin which enhances the binding of antithrombin to factor II and factor X. |
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Term
|
Definition
| Widely used to quantitate the concentration the concentration of a factor VIII inhibitor |
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Term
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Definition
| The amount of inhibitor that will inactive half of the factor during the incubation period |
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Term
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Definition
| An immunoglobulin that binds to phospholipids and proteins associated with the cell membrane. |
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Term
| What do lupus anticoagulant antibodies do? |
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Definition
| Cause an increase in inappropriate blood clotting. They also cause an increase in aPTT. |
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Term
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Definition
| Consists of the serine protease Factor Xa and the protein cofactor Va. |
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Term
| What does the prothrombinase complex do? |
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Definition
| Catalyzes the conversion of prothrombin (factor II) to thrombin (factor IIa) |
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Term
| What is another name for gray platelet syndrome? |
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Definition
|
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Term
| What is gray platelet syndrome? |
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Definition
| An automsomal-recessive disorder caused by a reduction or absence of alpha-granules in blood platelets. It involves lifelong mild bleeding with thrombocytopenia and enlarged platelets |
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Term
|
Definition
Helps certain clotting factors mature.
Adds a carboxyl group to glutamic acid residues
(Factors use these carboxylated residues to adhere to phospholipid surfaces and assemble multi-molecular coagulation complexes. |
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Term
| Which factors are Vitamin K-dependent clotting factors? |
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Definition
| Factors II (Prothrombin), VII, IX and X as well as proteins C,S and Z |
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Term
|
Definition
| Factor IIa, a serine protease that converts soluble fibrinogen into insoluble strands of fibrin |
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Term
| What is the role of thrombin? |
|
Definition
Activation of Factor XII
Activation of Factor XI to factor XIa
Activation of Factors V and VIII |
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Term
|
Definition
| Activated factors IX and VIII that work together to activate factor X |
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Term
| What does the tenase complex need to function? |
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Definition
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