Question | Answer |
Where does hematopoiesis take place from early fetal development to late fetal development and adult life? | Yolk Sac (2wks-2months)
Spleen and Liver (2-7months)
Bone marrow (7months-birth and through adult life) |
What are the purposes of making blood films? | Quality Control
Leukocyte diff and morphology evaluation
Evaluation of red cell distribution
Evaluation of red cell and platelet morphology |
At what angle should your spreader slide be when making a blood film? | 30-45 degrees |
What is the criteria for a good blood film? | Cover at least 2/3 to 3/4 of the slide
Homogenous with no gaps or streaks
No bullet shape (slightly curved)
Later edges visible
Should be easily labeled |
What should you do to your blood film if the patient has a low red cell count? | Blood is thin so raise the angle or increase the stroke speed |
What should you do to your blood film if the patient has a high red cell count? | Blood is thick so lower the angle and decrease the stroke speed |
What should you do to your blood film if you have a large drop? | Makes a longer, thicker smear. Raise the angle and increase the stroke speed |
What should you do to your blood film if you have a small drop? | Makes a shorter, thinner smear. Lower the angle and decrease the stroke speed. |
What structures attract the basic blue dye? | Acidic structures. DNA, RNA, immature or reactive cytoplasm, proteins, and acidic granules of basophils. |
What structures attract the acidic red dye? | The basic structures. Hemoglobin and basic granules in eosinophils |
What causes a too dark or too blue stain? | Prolonged staining
Inadequate washing
Stain too basic |
What cause a too pale or too red stain? | Insufficient staining
Prolonged washing
Stain to acidic |
The WBC/field in the feather edge should be ______ times more then WBC/field in the exam area. | < or equal to 4 times |
How do you correct platelet satellitism. | This reduces the PLT count so redraw into a sodium citrate tube. |
What is the order of red cell maturation according to CAP? | Pronormoblast
Basophilic normoblast
Polychromatic normoblast
Orthochromic normoblast
Polychromatic erythrocyte
Erythrocyte |
What is the order of red cell maturation according to ASCP? | Rubriblast
Prorubricyte
Rubricyte
Metarubricyte
Reticulocyte
Erythrocyte |
Erythropoietin is produced by what organ? | By the kidneys in response to tissue hypoxia |
Under normal conditions retics spend how much time in the bone marrow and PB? | 3 days in BM and 1 day in PB |
Under abnormal conditions retics spend how much time in the bone marrow and PB? | Less time in bone marrow, and more time in PB. |
What stage of maturation marks the beginning of hemoglobinization? | Polychromatic normoblast |
When should you do a corrected WBC count? | When there are 5 or more nRBCs. nRBCs increase the leukocyte count because they get mistaken for WBCs |
How do you calculate corrected WBC? | (Count x 100)/(# of nRBCs + 100) |
What is rouleax? | RBCs look like a stack of coins. Caused by abnormally high ration of serum proteins such as globulins and fibrinogen |
What is agglutination? | RBCs are clumped. Caused by presence of cold antibodies (IgM) This causes your RBC count and Hct to be lower, and your MCV will be higher |
What is a normal MCHC? | 32-36% g/dL |
What is hypochromasia? | When the central pallor is greater than 1/3 of the cell. Decreased Hgb. MCHC will be less than 32% |
What is polychromasia? | Increased reticulocyte count (blue cells) |
What is anisochromia? | Mixed cell population of normal cells and hypochromic cells |
What is a normal MCV? | 80-100 fL |
What is anisocytosis? | Variation in red blood cell size. Increases what the RDW |
Which red cell shape alterations are caused by abnormalities in the amount of the membrane lipid? | Target cells, echinocytes (burr cells), and acanthocytes (spur cells) |
Which red cell shape alterations are caused by abnormalities in the membrane proteins? | Elliptocytes/ovalocytes, stomatocytes, and spherocytes |
Which red cell shape alterations are caused by trauma? | Tear drops (dacrocytes), Schistocytes (fragment cells), Keratocyte (horned, helmut, or bite cell), and micropherules |
Which red cell shape alterations are caused by abnormalities in the Hgb molecule? | Hgb S, C, and SC |
What is poiklocytosis? | Variation in red cell shape |
Do spherocytes have a high or low MCHC? | High, >36% |
What causes basophilic stippling? | aggregates of ribosomes (RNA) |
When do you see basophilic stippling? | In lead poisoning and thalassemia |
What causes HJ bodies? | Remnants of DNA |
When do you see HJ bodies? | In megaloblastic anemia and poor spleen function |
What causes pappenheimer bodies? | clusters of unused iron |
When do you see pappenheimer bodies? | In sideroblastic anemia and iron overlaod |
What causes Heinz bodies? | denatured or precipitated Hgb |
When do you see Heinz bodies? | In G6PD deficiency. Visible only with supravital stain. |
What causes the Cabot ring? | Remnants of mitotic spindles |
What is a heme group? | Porphyrin ring with ferrous iron in the center |
What makes up the fetal Hgb (Hgb F)? | 2 alphas and 2 gammas |
What makes up the adult Hgb (Hgb A)? | 2 alphas and 2 betas |
What does it mean when you have a shift to the left in the OD curve? | Increase O2 affinity, decrease O2 release |
What things cause a shift to the left in the OD curve? | low H+ (high pH), low CO2, low temp, low DPG, low P50, high abnormal and fetal Hgb |
What does it mean when you have a shift to the right on the OD curve? | Decrease O2 affinity, increase O2 release |
What things cause a shift to the right in the OD curve? | High H+ (low pH), high CO2, high DPG, high temp, high P50, and anemia |
Which hemoglobin derivatives are irreversible? | Sulfhemoglobin and cyanmethemoglobin |
What is the reference method for measuring Hgb? | Cyanmethemoglobin |
What is Drabkins reagent made up of? | Potassium Ferricyanide K3Fe(CN)6
Potassium cyanide KCN |
What does potassium ferricyanide do? | Oxidizes ferrous iron to ferric iron (methemoglobin) |
What does potassium cyanide do? | Combines with methemoglobin to create cyanmethemoglobin |
All pigments are measured except for which one? | Sulfhemoglobin |
What can contribute to falsely elevated Hgb values? | Lipemia
Increase leukocyte count
RBC agglutination |
What is an inherent source of error with spun Hct? | Trapped plasma |
What are some technical source of errors with spun Hct? | Poor sealing
Anticoagulant ratio
Clots
Centrifugal force
Spin time
Misreading
Hemolysis |
How is Hct calculated? | (MCV x RBC count)/10 |
What is the rule of threes? | Hgb x 3 should equal Hct
RBC x 3 should equal Hgb
ONLY WORKS WITH NORMOCYTIC, NORMOCHROMIC |
The rate of erythrocyte settling depends on what? | The protein composition of the plasma
Size and shape of RBCs
RBC concentration
Viscosity of plasma |
What are some technical sources of error affecting the ESR? | Specimen is too old
Improper filing of ESR tube (bubbles)
Excess diluent and anticoagulant
Inaccurate timing
Temperature
Position of the tube (not vertical)
Vibration of ESR tubes
Hemolysis |
What stain should reticulocytes be stained with? | New methylene blue N (supravital stain) |
How do you calculate Retic percentage? | (# of retics/# RBCs) x 100 |
How do you calculate absolute retic count? | Retic % x RBC count |
How do you calculate correct retic count? | Retic % x (Pat Hct/45) |
How do you calculate RPI? | CRC/maturation time |
What is the principle of electrical impedance? | Based on increased resistance that occurs when a blood cell passes through and electrical field. (3 part diff) |
What is the principle of optical light scattering? | Based on light scattering measurements obtained as a single blood cell passes through a beam of light (5 part diff) |
Define anemia. | Decrease in the oxygen carrying capacity due to decreased number of RBCs or decreased Hgb content |
What is hypervolemia? | Increased plasma volume while RBC mass stays the same which causes falsely low Hgb and Hct |
What can cause hypervolemia? | IV fluid |
What is hypovolemia? | Decreased plasma volume while RBC mass stays the same which causes falsely high Hgb and Hct |
What can cause hypovolemia? | Dehydration and vomiting |
What is an example of an acute blood loss? | Gun shot wound |
What is an example of a chronic blood loss? | GI bleed |
How does an increase in heart rate and circulation rate affect blood flow? | Increases the flow of oxygenated blood to vital tissues such as brain and heart |
How does an increase in 2,3 DPG affect oxygen release? | Shifts OD curve to the right, thus more O2 is released to the tissues. |
How does an increase in anaerobic glycolysis? | Increases lactic acid which decreases pH and shifts OD curve to the right which means more O2 released to the tissues |
How do you calculate MCV? | (Hct/RBC) x 10 |
How do you calculate MCH? | (Hgb/RBC) x 10 |
How do you calculate MCHC? | (Hgb/Hct) x 100 |
What is a normal MCH? | 26-32 pg |