| 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 |
Biology Lab Midterm
