Questions | Answers |
The hemorrhagic problems assiciated with scurvy are due to a deficiency of ____________, which is a cofactor required for collagen synthesis. | Vitamin C |
approximately how many platelets dies an average megakaryocyte generate? | 2000 |
Thrombocytopenia may be caused by all the following EXCEPT
a. post-splenectomy
b. chemotherapy
c. decreased theombopoietin
d. aplastic anemia | a. post-splenectomy |
During the hemostatic process, platelets interacting with ans binding to other platelets is referred to as | aggregation |
In platelet aggregation studies, certain aggregating agents induce a biphasic aggregation curve. To what is the second phase of aggregation directly related? | release of endogenous ADP |
What is the operating principle of a platelet aggregometer? | change in optical density: as platelets aggregate, the optical density of the platelet-rich plasma decreases |
What platelet aggregation agent characteristically yields a biphasic pattern when used in optimal concentration? | epinephrine |
Which therapeutic agent affects platelet function? | aspirin |
Apotent inhibitor of platelet aggregation released by endothelial cells is | prostacyclin |
what is the approximate normal mean platelet volume (MPV) expressed in femtoliters (fL)? | 10 |
The platelet parameter PCW refers to the | variation in cell size |
What describes normal histograms showing platelet size distribution? | right-skewed, single peak |
For the performance of manuel platelet counts, what is the recommended type of microscopy? | phase |
20uL of blood are diluted in 1.98mL of diluent. This dilution is plated on both sides of a Neubauer-ruled counting chamber. 356 cells are seen when both large center squares are counted. What is the platelet count expressed as the number of cells/liter? | 178 X 10^9/L |
What size threshold range does the electrical impedance method use to count particules as platelets? | 2-20fL |
In storage pool diseases, lpatelets are primarily deficient in | ADP |
What is the specimen of choice for routine coagulation testing? | 3.2% (1.109M) sodium citrate |
The ratio of anticoagulant to blood for coagulation procedures should be 1 to | 9.0 |
The liver is the site of synthesis of all the following EXCEPT a. Factor VIII b. Plasmingogen c. Protein C d. von Willebrand's factor | d. von Willebrand's factor |
When thrombin binds with thrombomodulin on the endothelial cell surface, thrombin can | activate protein C |
What is the coagulation fdactor that has a sex-linked recessive inheritance pattern? | factor IX |
What is associated with individuals having a Prekallikrein deficiency? | can have thrombotic complications |
A soybean extract is used in specimen collection tubes for fibrin degradation product (FDP) tests to prevent | further fibrinogen degradation |
The thrombin time will be prolonged in the presence of | factor II deficiency |