2.1 Coagulation and Fibrinolytic Systems/Reagents and Methods Flashcards
Which of the following initiates in vivo coagulation by activation of factor VII?
Tissue factor (TF)
Which of the following clotting factors plays a role in clot formation in vitro, but not in vivo?
Factor XIIa
The anticoagulant of choice for most routine coagulation studies is:
Sodium citrate
Which anticoagulant:blood ratio is correct for coagulation procedures?
1:9
Which results would be expected for PT and APTT in a patient with polycythemia?
Both prolonged
Which reagents are used in the PT test?
Thromboplastin and calcium
Which test would be abnormal in a patient with factor X deficiency?
PT and APTT
Which clotting factor is not measured by the PT and APTT tests?
Factor XIII
A modification of which procedure can be used to measure fibrinogen?
TT
Which of the following characterizes vitamin K?
It is required for carboxylation of glutamate residues of some coagulation factors
Which fragments of fibrin clot degradation are measured by the D-dimer test?
The D-D domains
Which of the following clotting factors are measured by the APTT test?
Factors XII, XI, IX, VIII, X, V, II, I
Which coagulation test(s) would be abnormal in a patient with vitamin K deficiency?
PT and APTT
Which of the following is correct regarding the international normalized ratio (INR)?
A. It uses the international sensitivity ratio (ISR)
B. It standardizes PT results
C. It standardizes APTT results
D. It is used to monitor heparin therapy
It standardizes PT results
Which of the following is referred to as an endogenous activator of plasminogen?
Tissue plasminogen activator (tPA)
Which protein is the primary inhibitor of the fibrinolytic system?
α2-Antiplasmin
Which of the following statements is correct regarding the D-dimer test?
Test has a negative predictive value
A protein that plays a role in both coagulation and PLT aggregation is:
Factor I
A standard 4.5-mL blue-top tube filled with 3.0 mL of blood was submitted to the laboratory for PT and APTT tests. The sample is from a patient undergoing surgery the following morning for a tonsillectomy. Which of the following is the necessary course of action by the medical laboratory scientist?
Reject the sample and request a new sample
Which statement is correct regarding sample storage for the PT test?
Stable for 24 hours if the sample is capped
In primary fibrinolysis, the fibrinolytic activity results in response to:
Spontaneous activation of fibrinolysis
Plasminogen deficiency is associated with:
Thrombosis
Which of the following clotting factors are activated by thrombin that is generated by tissue pathway (TF-VIIa)?
Factors V, VIII
Which substrate is used in a chromogenic factor assay?
p-nitroaniline (pNa)
Which of the following antibodies is used in the D-dimer assay?
Monoclonal antibody against D-dimer
