1.1 Basic Hematology Concepts and Laboratory Procedures Flashcards
Insufficient centrifugation will result in:
A. A false increase in hematocrit (Hct) value
B. A false decrease in Hct value
C. No effect on Hct value
D. All these options, depending on the patient
- A. A false increase in hematocrit (Hct) value
Insufficient centri does not pack RBC, hence, Hct will increase
Hct (volume of packed cells)
Variation in RBC size observed on the PBS is described as:
A. Anisocytosis
B. Hypochromia
C. Poikilocytosis
D. Pleocytosis
- A. Anisocytosis
inc RDW = inc anisocytosis
Which of the following is the preferred site for bone marrow aspiration and biopsy in an adult?
A. Iliac crest
B. Sternum
C. Tibia
D. Spinous processes of a vertebra
- A. Iliac crest
it is the safest and preffered site for BM biopsy and aspiration
MCV is calculation using the formula:
A. (Hgb / RBC) x 10 where Hgb in g/dL
B. (Hct / RBC) x 10
C. (Hct / Hgb) x 100
D. (Hgb / RBC) x 100
- B. (Hct / RBC) x 10
MCV is the average volume of RBCs
What term describes the change in shape of erythrocytes seen on Wright-stained PBS?
A. Poikilocytosis
B. Anisocytosis
C. Hypochromia
D. Polychromasia
- A. Poikilocytosis
Calculate the MCHC by using the following values:
* Hgb = 15g/dL (150 g/L)
* RBC = 4.50 x10^6 /uL (4.50x10^12/L)
* Hct = 47 mL/dL (0.47)
A. 9.5% (0.095)
B. 10.4% (0.104)
C. 31.9% (0.319)
D. 33.3% (0.333)
MCHC = (hgb/hct) x 100
normal MCV: 32% to 36%
A manual WBC count was performed. In total 36 cells were counted in all 9-mm^2 squares of a Neubauer-ruled hemacytometer. A 1:10 dilution was used. What is the WBC count?
A. 0.4x10^9/L
B. 2.5x10^9/L
C. 4.0x10^9/L
D. 8.0x10^9/L
- A. 0.4x10^9/L
36x10x10 / 9 = 400
WBC count = no. cells x dF x depth factor 10 / area
When an erythrocyte containing iron granules is stained with Prussian blue, the cell is called a:
A. Spherocyte
B. Leptocyte
C. Schistocyte
D. Siderocyte
- D. Siderocyte
Siderocytes are RBC containing iron granules
visible when stained with prussian blue
A 7.0-mL EDTA tube is received in the laboratory containing only 2.0-mL of blood. If the laboratory is using manual techniques, which of the following tests will most likely be erroneous?
A. RBC count
B. Hgb
C. Hct
D. WBC count
- C. Hct
excessive anticoagulant causes shrinkage of cells, hct will be affected.
A 1:200 dilution of patient’s sample was made, and 336 RBCs were counted in an area of 0.2 mm^2. What is the RBC count?
A. 1.68x10^12/L
B. 3.36x10^12/L
C. 4.47x10^12/L
D. 6.66x10^12/L
- B. 3.36x10^12/L
RBC ct = 336x200x10 / 0.2
= 3.36x10^6 /mm^3 or 3.36x10^12/L
What phagocytic cells produce lysozymes that are bacteriocidal?
A. Eosinophils
B. Basophils
C. Platelets
D. Neutrophils
- D. Neutrophils
neutrophils are highly phagocytic
If the patient has a reticulocyte count of 7% and Hct of 20%, what is the corrected reticulocyte?
A. 1.4%
B. 3.1%
C. 3,5%
D. 14%
- B. 3.1%
corrected retics ct = (retics ct) (hct/45)
A decreased osmotic fragility test would be associated with which of the following conditions?
A. Sickle cell anemia
B. Hereditary spherocytosis
C. Hemolytic disease of the fetus and newborn
D. Acquired hemolytic anemia
- A. Sickle cell anemia
OFT is decreased in numerous sickle cells & target cells
OFT is increased in presence of spherocytes which are prominent feature of HS, HDFN, Acquired hemolytic anemia.
What effect would using a buffer at pH 6.0 have on a Wright-stained smear?
A. RBCs would be stained too pink
B. WBC cytoplasm would be stained too blue
C. RBCs would be stained too blue
D. RBCs would lyse on the slide
- A. RBCs would be stained too pink
pH is too low (<6.4), so RBCs take up more acidic dye (eosin) = too pink
Which of the following erythrocyte inclusions can be visualized with supravital stain but cannot be detected on a Wright-stained blood smear?
A. Basophilic stippling
B. Heinz bodies
C. Howell-Jolly bodies
D. Siderotic granules
- B. Heinz bodies
irregular, refractile, purple inclusions not visible in wright stain
A falsely elevated Hct is obtained. Which of the following calculated values will not be affected?
A. MCV
B. MCH
C. MCHC
D. RDW
- B. MCH
MCH = (hgb/rbc) x10
A miller disk is an ocular device used to facilitate counting of:
A. PLT
B. Retics
C. Sickle cells
D. NRBCs
- D. NRBCs
SITUATION: RBC indices obtained on an anemic patient are as follows: MCV 88um^3 (fL); MCH 30pg; MCHC 34% (0.340). The RBCs on the PBS would appear:
A. Microcytic, hypochromic
B. Microcytic, normochromic
C. Normocytic, normochromic
D. Normocytic, hypochromic
- C. Normocytic, normochromic
all within normal referenc range
MCV = 80-100 fL
MCHC = 32-36%
All of the following factors may influence the ESR, except:
A. Blood drawn from sodium citrate tube
B. Anisocytosis, poikilocytosis
C. Plasma proteins
D. Caliber of the tube
- A. Blood drawn from sodium citrate tube
EDTA & Sodium Citrate can be used without any effect on ESR
anisocytosis & poikilocytosis impede rouleaux formation, plasma proteins enhance rouleaux
What staining method is used most frequently to stain and manually count reticulocytes?
A. Immunofluorescence
B. Supravital staining
C. Romanowsky staining
D. Cytochemical staining
C. Supravital staining
reticulum w/in retics consists of RNA w/c cannot be stained w/ wright
The Coulter principle for counting of cells is based on the fact that:
A. Isotonic solutions conduct electricity better than cells do
B. Conductivity varies proportionally to the number of cells
C. Cells conduct electricity better than saline does
D. Isotonic solutions cannot conduct electricity
- A. Isotonic solutions conduct electricity better than cells do
Electronic cell (Coulter) counter use principle of electrical impedance
A correction is necessary for WBC counts when NRBCs are seen on the PBS because:
A. WBC ct would be falsely lower
B. RBC ct is too low
C. NRBCs are counted as leukocytes
D. NRBCs are confused with giant PLTs
- C. NRBCs are counted as leukocytes
to correct: (uncor WBC ct / (NRBCs + 100) x 100
Using an electronic cell counter analyzer, an increased RDW should correlate with:
A. Spherocytosis
B. Anisocytosis
C. Leukocytosis
D. Presence of NRBCs
- B. Anisocytosis
RDW is directly proportional with the degree of Anisocytosis
RDW ref range: 11.5% to 14.5%
Given the following values, which set of RBC indices suggests spherocytosis?
A. MCV 76fL MCH 19.9pg MCHC 28.5%
B. MCV 90fL MCH 30.5pg MCHC 32.5%
C. MCV 80fL MCH 36.5pg MCHC 39.0%
D. MCV 81fL MCH 29.0pg MCHC 34.8%
- C. MCV 80fL MCH 36.5pg MCHC 39.0%
In spherocytosis, index most affected is MCHC >36%
