heme externship - coag 2.1-2.2 Flashcards
which of the following initiates in vivo coagulation by activation of factor VII
A. protein C
B. tissue factor
C. plasmin activator
D. thrombomodulin
B. tissue factor
- tissue factor + calcium activates FVII in extrinsic pathway
which of the following clotting factors plays a role in clot formation in virto, but not in vivo
A. FVIIa
B. FIIa
C. FXIIa
D. FXa
C. FXIIa
- bypassed by contact activation in test systems
the anticoagulant of choice for most routine coagulation studies is
A. sodium oxalate
B. sodium citrate
C. heparin
D. EDTA
B. sodium citrate
which anticoagulant:blood ratio is correct for coagulation procedures
A. 1:4
B. 1:5
C. 1:9
D. 1:10
C. 1:9
which resutls would be expected for PT and APTT in a patient with polycythemia
A. both prolonged
B. both shortened
C. normal, prolonged APTT
D. both normal
A. prolonged
- due to excess anticoagulant and low plasma volume
which reagents are used in the PT test
A. thromboplastin and sodium chloride
B. thromboplastin and potassium chloride
C. thromboplastin and calcium
D, actin and calcium chloride
C. thromboplastin and calcium
which test would be abnormal in a patient with FX deficiency
A. PT only
B. APTT only
C. PT and APTT
D> TT
C. PT and APTT
- FX is in common pathway so both are impacted
which clotting factor is NOT measured by the PT and APTT tests
A. FVIII
B. FIX
C. FV
D. FXIII
D. FXIII
- necessary for clot stabilization in vivo but not measured
a modification of which procedure can be used to measure fibrinogen
A. PT
B. APTT
C. TT
D. fibrin degradation products
C. TT
which of the following characterized vitamin K
A. it is required for biological activity of fibrinolysis
B. its activity is enhanced by heparin therapy
C. it is required for carboxylation of glutamate residues of some coagulation factors
D. it is made by endothelial cells
C. it is required…
- magic 4 factors (II, VII, IX, X) need to be carboxylated to be functional in the liver
which fragments of fibrin clot degradation are measured by the D-dimer test
A. fragments X and Y
B. fibrinopeptide A and B
C, fragments of D and E
D. D-D domains
D. D-D domains
- present in ONLY secondary fibrinolysis
which of the following clotting facotrs are measured by the APTT test
A. II, VII, IX, X
B. VII X, V, II, I
C. XII, XI, IX, VII, X, V, II, I
D. XII, VII, X, V, II, I
C. intrinsic pathway
which coagulation test(s) would be abnormal in a patient with vitamin K deficiency
A. PT only
B. PT and APTT
C. fibrinogen level
D. TT
B. PT and APTT
- Factors: II, VII, IX, X impacted
which of the following is correct regarding the INR
A. it uses the international sensitivity ratio (ISR)
B. it standardized PT results
C. it standardizes APTT results
D. it is used to monitor heparin therapy
B. it standardizes PT results
which of the following is referred to as an endogenous activator of plasminogen
A. streptokinase
B. transamidase
C. tissue plasminogen activator (tPA)
D. tPA inhibitor
C. tPA
- released from endothelial cells by protein C
which protein is the primary inhbitor of the fibrinolytic system
A. protein C
B. protein S
C. alpha2-antiplasmin
D. alpha2-macroglobulin
C. alpha2-antiplasmin
- binds free plasmin
which of the following statements is correct regarding the D-dimer test
A. levels are decreased in DIC
B. test detects polypeptides A and B
C. test detects fragments of D and E
D. test has a negative predictive value
D. test has a negative preditive value
- probability that a negative result is free of disease
a protein that plays a role in both cogulatin and PLT aggregatin is:
A. FI
B. FVIII
C. FIX
D. FXI
A. FI (fibrinogen)
- platelets use fibrinogen to aggregate together
a standard 4.5 mL blue top tube filled with 3.0 mL of blood was submitted to the lab for PT and APTT. the sample is from a patient undergoing surgery the following morning for a tonsillectomy. Which of the following is necessary course of action by the medical lab scientist
A. run both tests in duplicate and report the average result
B. reject the sample and request a new sample
C. report the PT
D. report the APTT
B. reject due to nonsufficient quantitiy