HEMA 1 EXAM Flashcards
The bevel of the needle should be held ______ in the performance of a venipuncture.
A. sideways
B. upward
C. downward
D. in any direction
upward
*bevel of the needle should be upward to penetrate the skin and avoid difficulty in obtaining the specimen
A blood sample is need from a patient with IV fluids running in both arms. Which of the following is an acceptable procedure?
A. Any obtainable vein is satisfactory.
B. Obtain sample from above the IV site.
C. Obtain sample from below the IV site with special restrictions.
D. Disconnect the IV line.
Obtain sample from below the IV site with special restrictions.
*A limb with an IV running should not be used for
venipuncture because of contamination to the specimen. The patient’s other arm or an alternate site should be selected. If no alternate site can be found, the IV should be turned off by the physician
and blood can be drawn from below the infusion site after a few minutes.
Which of the following skin puncture areas is acceptable for the collection of capillary blood from an infant?
A. Previous puncture site
B. Posterior curve of the heel
C. Arch
D. Medial or lateral plantar surface
Medial or lateral plantar surface
Capillary Blood Collection: Appropriate Site
INFANT:
medial or lateral plantar surface of the heel, with a puncture no deeper than 2.0mm beneath the plantar heel-skin surface and no more than half this distance at the posterior curve of the heel
ADULT:
Fingertip (3rd or 4th finger); Earlobe
Which parameters are calculated rather than directly measured?
A. Hematocrit and erythrocyte distribution width
B. Erythrocyte count and leukocyte count
C. Leukocyte count and hematocrit
D. Platelet count and platelet volume
Hematocrit and erythrocyte distribution width
*Directly
Measured: RBC and WBC count, Hemoglobin
Calculated: Hct, RDW
The delta check is used to detect
A. the use of the correct anticoagulant
B. The time of storage of a tested specimen
C. the difference between current and past patient results
D. the proper collection time of a patient specimen
The difference between current and past patient
results
*Delta checks are particularly important to rule out mislabeling, clerical error, or possibly an analytical error. It is another quality control method for comparing a patient’s own leukocyte, hemoglobin, MCV, and platelet values with previous results.
A peripheral blood smear can be prepared from
A. EDTA-anticoagulated blood within 1 hour of collection
B. Free-flowing capillary blood
C. Citrated whole blood
D. Both A and B
Both A and B
*The preparation of a blood smear may be conducted at the patient’s bedside or in the laboratory, if EDTA anticoagulated blood is used. Although, free-flowing capillary blood may be used as well.
Your co-intern keeps on making a blood smear that is too long, this can be resolved by:
A. Decreasing the angle of the pusher slide
B. Increasing the angle of the pusher slide
C. Using a larger drop of blood
D. Pushing the slide slower in smearing out the blood
Increasing the angle of the pusher slide
TOO LONG/TOO THIN
-Using a smaller drop of blood; Increasing the angle of the pusher slide
TOO SHORT/TOO THICK
-Using a larger drop of blood; Decreasing the angle of the pusher slide
FEATURES OF A GOOD BLOOD SMEAR PREP
1. The film is two thirds to three fourths the length of the slide.
- The film is finger shaped, very slightly rounded at the feather edge, not bullet shaped; this provides the widest area for examination.
- The lateral edges of the film are visible.
- The film is smooth without irregularities, holes, or streaks.
- When the slide is held up to the light, the thin portion (feather edge) of the film has a “rainbow” appearance.
- The whole drop of blood is picked up and spread.
If a blood smear stains too red on microscopic examination of a Wright-stained preparation,
possible causes include that
A. the staining time was too long
B. the stain was too basic
C. the buffer was too acidic and the exposure time was too short
D. the buffer was too basic and the exposure time was too long
the buffer was too acidic and the exposure time was too short
*Wright stain is composed of a basic dye (Methylene blue) and acidic dye (Eosin). The overall color and intensity of staining in a Wright-stained blood smear
vary with cell maturity and type, so proper staining is crucial for proper identification.
In the S phase of mitotic division, how long does DNA replication occurs?
A. 1 hour
B. 2 hours
C. 4 hours
D. 8 hours
8 hours
Which of the following is NOT a function of a quantitative QC program?
A. Detects shifts in control values
B. Compares the accuracy of controls to reference values
C. Monitors the correct functioning of equipment,
reagents, and individual technique
D. Confirms the correct identity of patient specimens
Confirms the correct identity of patient specimens
- QC activities include monitoring the performance of laboratory instruments, reagents, other testing products, and equipment.
- A written record of QC activities for each procedure or function should include details of deviation from the usual results, problems, or failures in functioning or in the analytical
(examination) procedure and any corrective action taken in response to these problems.
Acceptable limits of a control value must fall
A. within +1 standard deviation of the mean
B. between 1 and 2 standard deviations of the mean
C. within ‡2 standard deviations of the mean
D. within ‡3 standard deviations of the mean
within ‡2 standard deviations of the mean
*Confidence or control limits are calculated from the mean and the SD. The confidence limits represent a set of mathematically established limits into which the majority of values (results) will fall. Within the confidence limits, the results are assumed to be accurate. It is common practice to use ±2 SD as the limit of confidence.
Which characteristic is inaccurate with respect to the anticoagulant K3 EDTA?
A. Removes ionized calcium (Ca2+) from fresh whole blood by the process of chelation
B. Is used for most routine coagulation studies
C. Is the most commonly used anticoagulant in hematology
D. Is conventionally placed in lavender-stoppered evacuated tubes
Is used for most routine coagulation studies
EDTA: Most common anticoagulant used in Hematology Laboratory
Lavender – Hematology tests
Pink - Bloodbanking
Royal Blue – Toxic Elements
Tan – Lead Determination
White – Molecular studies
Citrate: Used in routine coagulation studies
The normal sequence of blood cell development is
A. Liver and spleen—yolk sac—red bone marrow
B. Yolk sac—red bone marrow—liver and spleen
C. Yolk sac—thymus—liver and spleen—red bone marrow
D. Yolk sac–liver and spleen—red bone marrow
Yolk sac–liver and spleen—red bone marrow
MESOBLASTIC: First cell to be produced: erythroblasts
- Occurs early in embryonic
development, cells from the
mesoderm migrate to the
yolk sac
HEPATIC: Liver becomes the major site of hematopoiesis; but other organs such as spleen, kidney, thymus, and lymph
node also contribute to the process
MEDULLARY: At the end of 24 weeks gestation, Bone marrow becomes the primary
site of hematopoiesis.
By age 18, red marrow can be found in the
A. Skull bones
B. Vertebrae and ribs and Skull bones
C. Skull bones, Sternum and pelvis, Vertebrae and ribs
D. None of the above
Skull bones, Sternum and pelvis, Vertebrae and ribs
*By age 18, red marrow is found only in the vertebrae, ribs, sternum, skull bones, pelvis, and, to some extent, the proximal epiphyses of the femur and humerus.
* During infancy and early childhood, all the bones in the body contain primarily red (active) marrow.
* When retrogression occurs, hematopoietically
inactive yellow marrow is scattered throughout the red marrow so that, in adults, there is approximately equal amounts of red and yellow marrow. (Rodak 6th ed., 2020)
What is the first type of cell produced by the developing embryo?
A. Erythrocyte
B. Granulocyte
C. Lymphocyte
D. Thrombocyte
Erythrocyte
Yolk Sac or Mesoblastic phase
-From the developing embryo,
erythroblasts are produced
Medullary or Myeloid Phase
- An increase in the production of granulocytes cause an increase of M:E ratio
As a blood cell matures, the overall cell diameter in
most cases
A. increases
B. decreases
C. remains the same
decreases
What is the immature erythrocyte found in the
bone marrow with the following characteristics: 12 to 17 mm in diameter, N:C of 4:1, nucleoli not usually apparent, and basophilic cytoplasm?
A. Rubriblast (pronormoblast)
B. Reticulocyte
C. Metarubricyte (orthochromatic normoblast)
D. Prorubricyte (basophilic normoblast)
Prorubricyte (basophilic normoblast)
With a normal diet, an erythrocyte remains in the
reticulocyte stage in the circulating blood for
A. 1 day
B. 2.5 days
C. 3 days
D. 120 days
1 day
*Life span of RBCs: 120 days
Remains in the
Reticulocyte stage: 1 day
Increased amounts of 2,3-DPG______ the oxygen affinity of the hemoglobin molecule.
A. Increases
B. Decreases
C. Do not alter
Decreases
Which condition will shift the oxyhemoglobin dissociation curve to the right?
A. Acidosis
B. Alkalosis
C. Multiple blood transfusions
D. Increased quantities of Hb S or C
Acidosis
- Acidosis is associated with a shift to the right of the oxyhemoglobin dissociation curve and, therefore, increased oxygen release (decreased
affinity of Hgb for oxygen). - Multiple blood transfusions shift the curve to the left because the transfused blood is low in 2,3-DPG.
- Hgb S and Hgb C do not change the affinity of oxygen for hemoglobin; however, many
hemoglobinopathies do.
The most common erythrocytic enzyme deficiency involving the Embden-Meyerhof Glycolytic Pathway (EMP) is a deficiency of
A. ATPase
B. PK
C. G6PD
D. LD
PK
EMP
- Pyruvate Kinase (PK)
-Maintains cellular energy by
generating ATP
HMP
-Glucose-6-phosphate
dehydrogenase (G6PD) Prevents denaturation of globin by oxidation
Rapoport- Luebering Pathway
-Permits the accumulation of
2,3-DPG; regulates oxygen
affinity of hemoglobin
Methemoglobin Reductase Pathways
-Prevent oxidation of heme iron;
maintains iron into functional
state (ferrous)
If you are grading changes in erythrocytic size or shape using a scale of 0 to 4+ and many erythrocytes deviate from normal per microscopic field, the typical score would be
A. 1+
B. 2+
C. 3+
D. 4+
3+
0 - Normal appearance or slight variation in erythrocytes.
1+ Only a small population of erythrocytes displays a particular abnormality; the terms slightly increased or few would be comparable.
2+ More than occasional numbers of abnormal
erythrocytes can be seen in a microscopic field; an equivalent descriptive term is moderately increased.
3+ Severe increase in abnormal erythrocytes in each microscopic field; an equivalent descriptive term is many.
4+ The most severe state of erythrocytic abnormality, with the abnormality prevalent
throughout each microscopic field; comparable terms are marked or marked increase.
Heinz bodies can be observed in cases of
A. Pernicious anemia
B. G6PD deficiency
C. Iron loading anemia
D. Lead poisoning
G6PD deficiency
Which of the following is the term for erythrocytes resembling a stack of coins on thin sections of a peripheral blood smear?
A. Anisocytosis
B. Poikilocytosis
C. Agglutination
D. Rouleaux formation
Rouleaux formation
Anisocytosis
- Variation in size
Poikilocytosis
-Variation in shape
Agglutination
-Clumping of erythrocytes, caused by the presence of antibodies reacting with antigens on the erythrocyte
Rouleaux formation
-Arrangement of erythrocytes in
groups that resemble stacks of coin; associated with the presence of cryoglobulins
Rouleaux of red blood cells when seen in the monolayer of blood smear is a characteristic of:
A. Hypersplenism
B. Hypogammaglobulinemia
C. Cold Hemagglutinin Disease
D. Multiple Myeloma
Multiple Myeloma
*Multiple Myeloma – a clonal plasma cell neoplasm
associated with abnormal protein production, particularly immunoglobulins. IgG antibodies are found in majority of the patients.
The abnormal protein frequently found in the urine of persons with multiple myeloma is
A. albumin
B. globulin
C. IgG
D. Bence Jones
Bence Jones
*Urine tests for Bence Jones protein has been clinically
significant in the identification of Multiple Myeloma.
Howell-Jolly bodies are composed of
A. DNA
B. Iron
C. RNA
D. Hemoglobin
DNA
Howell-Jolly bodies
-DNA; Feulgen Stain (+)
Pappenheimer bodies
-Iron
Basophilic Stippling
-RNA; Aggregated ribosomes
Heinz Bodies
-Denatured Hemoglobin
Which of the following inclusions is only visible with
supravital staining?
A. Basophilic Stippling
B. Cabot rings
C. Heinz Bodies
D. Pappenheimer bodies
Heinz Bodies
RHH: only visible with supravital stains
R - Reticulocytes
H - Heinz bodies
H - Hb H
If a male patient has a reticulocyte count of 5% and a packed cell volume of 0.45 L/L, what is his corrected reticulocyte count?
A. 2.5%
B. 4.5%
C. 5.0%
D. 10%
5.0%
CRC: %retics x Hct/45
On a Wright-stained peripheral blood smear, stress or shift reticulocytes are
A. Smaller than normal reticulocytes
B. About the same size as normal reticulocytes
C. Larger than normal reticulocytes
D. Noticeable because of a decreased blue tint
Larger than normal reticulocytes
*Stress of shift reticulocytes are released by the BM to compensate during anemia, which is why they are larger than normal retics.
If a febrile, newborn infant had 4 nucleated red blood cells when a 100 cell WBC differential was performed, how would this be interpreted?
A. Lymphocytes were mistaken for nucleated red blood cells.
B. The baby was suffering from hemolytic disease of the fetus and newborn (HDFN).
C. Nucleated red blood cells can be expected in febrile patients.
D. During the first few days of life, the presence of a few nucleated red blood cells is normal.
During the first few days of life, the presence of a few nucleated red blood cells is normal.
*Orthochromic normoblasts often are identified in the
full-term infant on the first day of life but disappear within postnatal days 3 to 5. These nucleated RBCs (NRBCs) may persist longer than a week in immature infants.
The average number of NRBCs ranges from 3 to 10 per 100 white blood cells (WBCs) in a healthy full-term infant to 25 NRBCs per 100 WBCs in a premature infant.
The erythrocyte morphology associated with anemia in an otherwise healthy individual caused by acute blood loss is usually
A. Microcytic
B. Megaloblastic
C. Normochromic
D. Hypochromic
Normochromic
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 of these options, depending on the patient
A false increase in hematocrit (Hct) value
*Insufficient centrifugaBon does not pack down the red blood cells; therefore, the Hct, which is the volume of packed cells, will increase.
A 7.0 ml ethylenediaminetetraacetic acid (EDTA) tube is received in the laboratory containing only 2.0mL of blood. If the laboratory is using manual
techniques, which of the following tests will most likely be erroneous?
A. RBC count
B. Hemoglobin (Hgb)
C. Hct
D. WBC count
Hct
Excessive anticoagulant causes shrinkage of cells; thus, the Hct will be affected. RBC and WBC counts remain the same, as does the Hgb content.
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 newborn
D. Acquired hemolytic anemia
Sickle cell anemia
*Osmotic fragility is decreased when numerous sickle cells and target cells are present and is increased in the presence of spherocytes.
A falsely elevated Hct is obtained. Which of the following calculated values will NOT be affected?
A. MCV
B. MCH
C. MCHC
D. Red cell distribution width (RDW)
MCH
*The red cell distribution width (RDW) is calculated by electronic cell counters and reflects the variance in the size of the red cell population. Electronic cell counters calculate Hct from the MCV and RBC count. Therefore, the RDW would be affected by an erroneous MCV.
All of the following factors may influence the erythrocyte sedimentation rate (ESR) EXCEPT
A. Blood drawn into a sodium citrate tube
B. Anisocytosis, poikilocytosis
C. Plasma proteins
D. Caliber of the tube
Blood drawn into a sodium citrate tube
- EDTA and Sodium citrate can be used without any effect on the ESR.
- Anisocytosis and poikilocytosis may impede rouleaux formation, thus causing a low ESR.
- Plasma proteins, especially fibrinogen and immunoglobulins, enhance rouleaux, increasing the ESR. Reference ranges must be established for different caliber tubes.
Modified Westergren: currently the most commonly used method for ESR
Westergren:
- Anticoagulant: Citrate
- Ratio of Anticoagulant to Blood: 1:4
- Color of Stopper: Black
A correction is necessary for WBC counts when nucleated RBCs are seen on the peripheral blood smear because:
A. The WBC count would be falsely lower
B. The RBC count is too low
C. nRBCs are counted a leukocytes
D. nRBCs are confused with giant plts
nRBCs are counted a leukocytes
*The automated hematology analyzers enumerate all
nucleated cells. nRBCs are counted along with WBCs,
falsely elevating the WBC count.
Formula:
corrected= Uncorrected WBC ct. x 100 / nRBC + 100
The Coulter principle for counting of cells is based upon 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
Isotonic solutions conduct electricity better than cells do
- Electronic cell (Coulter) counters use the principle of electrical impedance.
- Two electrodes suspended in isotonic solutions are separated by a glass tube having a small aperture.
- A vacuum is applied, and as a cell passes through the aperture it impedes the flow of current and generates a voltage pulse.