Exam 3 Flashcards
How is the promyelocyte differentiated from the myeloblast?
Promyelocyte has azurophilic (primary) granules
At what stage does differentiation of the granules of the cells of the myelocytic series take place?
myelocyte
How is the metamyelocyte differentiated from the myelocyte?
Shape of nucleus:
Meta => kidney bean shaped
Myelo => round
How is the band differentiated from the metamyelocyte?
Shape of nucleus:
Band => horse shoe shaped (uniform thickness)
What cell contains granules that retain the acid portion of Wright’s stain?
eosinophil (acid stain = eosin)
What substances are produced by eosinophils?
anti-histamine
basophils produce histamine
What cell contains granules that are not uniform in shape, stain with the basic portion of Wright’s stain, and may cover the nucleus?
basophils
What are mast cells?
tissue basophils
Where do B cells originate?
bone marrow
Where do T cells originate?
thymus
How can B cells and T cells be differentiated?
through surface markers (surface immunoglobulins)
What type of lymphocyte (B cell or T cell) are most of the circulating lymphocytes and what is their appearance?
T-cell. Small, mature lymphs; clumping nucleus, not much cytoplasm
During blastic transformation, B cells become what?
plasma cells
What cell has an eccentric nucleus with clumped chromatin, basophilic cytoplasm, and a clear perinuclear halo (hof)?
plasma cell
Where are plasma cells normally found?
bone marrow
What cellular organelle is associated with the hof?
Golgi apparatus
Monocytes circulate in the peripheral blood but are known as __________ or __________ in the tissues.
macrophages or histiocytes
Where do monocytes originate?
bone marrow
What is the function of the monocyte?
phagocytosis
Name several characteristics that can be observed in neutrophils during inflammation, infection, or other toxic states and describe their appearance.
Dohle bodies: RNA
toxic granules: blue/black granules in cytoplasm
toxic vacuoles: holes in cytoplasm
What are Russell bodies?
aggregates of immunoglobulin that stain red
Describe Alder-Reilly.
abnormal azurophilic granulation
Describe May-Hegglin.
Weird platelets, Dohle-like inclusions, blue staining
Describe Pelger-Huet.
dumbbell shaped hyposegmentation of neutrophils
What is the normal WBC count?
5-10 thousand
If blood is drawn to the 0.5 mark and diluent to the 11 in a WBC pipette, what is the resulting dilution?
standard WBC count, 1:20 dilution
Given the number of cells counted on both sides of the hemocytometer, how could you determine the WBC count on the performance of a standard WBC count?
average of both counts x 50
Ex: 120100/2 is the same as 11050
What effect does hemolysis have on a WBC count?
none
Name several sources of error in the performance of a manual WBC count.
too much blood/diluent overfill/underfill hemocytometer cracks edema dirty hemocytometer
How does the normal WBC count vary during the day?
WBC’s hang on wall at night and fall off with activity during the day. higher during day lower at night
What explanation is given for the variation of WBC counts?
margination
What is the normal eosinophil count?
77-440
What can cause an increased or decreased eosinophil count?
Increased: hypoadrenalism; allergies;parasitic infections; skin disorders; blood diseases
Decreased: anemia; hyperadrenalism (Cushings disease);IM; Pern. anemia; aplastic anemia
To compensate for the normally low number of eosinophils, what adjustment in the procedure is made when doing a manual eo count?
increase # fields increase volume (entire hemocytometer)
Name two other hemocytometers that can be used for eosinophils and basophil counts.
Speirs-Levy
Fuchs-Rosenthal
Name several factors that can results in an excessively pink Wright’s stained smear.
too acidic- overwashed or understained
Name several factors that can result in an excessively blue Wright’s stain smear.
too alkaline- underwashed or overstained
What three things are always performed when doing a differential count?
Why?
RBC morphology
count and classify 100 cells
platelet count estimation
Used for: Dx disease, monitor therapy, or to get picture of overall health.
What is the most common type of WBC in a normal smear?
segmented neutrophils
`What is the least common type of WBC in a normal smear?
basophils
What is the most common type of WBC in a child’s smear?
lymphocytes
What is a “shift to the left” and in what conditions is it likely to occur?
increase in young cells (increase in bands)
occurs in CML (infection); leukemias; bacterial infections
What is the largest WBC in a normal peripheral blood smear?
Monocyte
Which cells are classified as NRBCs on a PBS?
blast cells, prorubricytes, rubricytes, metarubricytes
If large numbers of NRBCs are observed on a PBS, what effect will this have on the WBC count?
they are counted as WBCs, this will increase the WBC count
may falsely increase the white count
How can you correct your count for NRBCs?
(WBC x 100)/(100+NRBCs)
Where are platelets produced?
Bone marrow
What is the largest blood cell normally produced by the body?
Megakaryocyte
What is endomitotic division?
POSSIBLE BONUS QUESTION
Nucleus divides, cytoplasm just enlarges. Multinucleated cell.
What is the normal platelet count?
Varies greatly. For this test:
150,000-450,000/mm3
What method employs the phase contrast microscope in counting platelets?
Brecker Cronkite
How is a manual platelet count calculated using the Unopette method?
Entire center square = 0.1 mm^3
1: 100 dilution
0. 1/100 = 1000
So: # cells * 1000
What criteria are used to estimate platelets in a PBS?
PLT estimates are routinely performed using a 100X oil objective in an area of the smear where the red blood cells (RBCs) barely touch. A rough estimate can be determined by the number of platelets per 100X oil-immersion field (OIF). References state that anywhere from 7 to 22 platelets per OIF correlates with a normal platelet count.
Reddish-purple in blast inclusion
Auer rod
Pale blue remnants of RNA
Dohle bodies
Decreased segmentation of neutrophils
Pelger-Huet
Dark blueish black cytoplasm granules
Toxic granulation
Azurophilic granulation of all white cells
Alder-Reilly
