MLT 120 Exam III Flashcards
How is a 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; cytoplasm
meta - kidney bean shaped
myelo - round; bluish tint
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?
What substances are produced by these granules?
eosinophil (acid stain=eosin)
anti-histamine
usually only have two lobes
basophils produce histamine
What cell contains granules that are not uniform in shape, stain with the basic portion of Wright’s stain, and which may cover the nucleus?
basophils (basic stain=methylene blue)
What are mast cells?
tissue basophils
Where do B cells originate?
bone marrow
Where to T cells originate?
thymus
How do you distinguish B cells from T cells?
surface markers ( surface immunoglobulins; on Tcells)
hairy b cellsexception
During blastic transformation B cells become
plasma cells
What cell has an eccentric nucleus with clumped chromatin, basophilic cytoplasm and a clear perinuclear halo (hof)?
plasma cells
Where are plasma cells normally found?
bone marrow
exception in multiple myeloma pt.
What cellular organelle is associated with the hof?
golgi apparatus
Monocytes circulate in the peripheral blood but are known as _______ in the tissues?
macrophages or histocytes
Where do monocytes originate?
bone marrow
How would you describe a monocyte according to the following: appearance of chromatin shape of nucleus color of cytoplasm presence of pseudopodia or vacuoles
chromatin not coarse or clumpy
nucleus is globulinated, coarse
pseudopodia
vacuoles
What is the function on the monocyte?
phagocytosis
Name several charateristics that can be observed in the meutrophils 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 stains red
found in lymphocytes
abnormal azurophilic granulation of white cells
Alder-Reilly
abnormal platelets, Dohle like inclusions, blue staining
May-Hegglin
dumbbell shaped, hyposeg (decreased segmentation) of neutrophils
Pelger-Huet
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 white blood cell 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 both sides, times by 50
What effect does hemolysis have on a WBC count?
none; rbc should hemolysis
Name several sources of error in the performance of a manual WBC count.
too much blood
diluent overfill
underfill hemocytometer
contamination
How does the normal WBC count vary during the day?
What explanation is given for this variation?
higher in the evening, lower during the day
margination
What is the normal eosinophil count?
What causes and increase or decrease?
77-440
increase - hypoadrenalism, allergic reaction, parasitic infection, skin disease
decrease - hyperadrenalism, anemia,
thorn test, ACTH to decrease eos count
To compensate for the normally low number of eosinophils, what adjustment in the procedure is made when doing a manual eo count?
increase # of fields which increases volume counted
Name two other hemocytometers that can be used for the eos and basophil counts.
Speirs-Levy
Fuchs-Rosenthal
increased volume
Name several factors that can result in an excessively pink Wright’s stained smear.
too acidic
over washed
under stained
Excessively blue Wright’s stained smear
too basic
under washed
over stained
What three things are always performed when doing a differential count?
RBC morphology count
platelet count estimation
count and classify 100 white blood cells
What is the most common type of WBC in a normal smear?
least common?
most common in a child?
segmented neutrophils
basophils
lymphocytes
What is a ‘shift to the left’ and what conditions is it likely to occur?
increase in bands, young cells; occurs in bacterial infection, inflammation, pregnancy
What is the largest WBC in normal peripheral blood smear?
monocyte
Which cells are classified as nRBCs on a PBS?
which still have nucleus: blast cells prorubricytes rubricytes metarubricytes
If a large number of nRBCs are observed on a PBS, what effect will this have on the WBC count?
How can you correct for this?
they are counted as WBCs, this will increase the WBC count (may falsely increase WBC count)
(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 the endomitotic division?
nucleus divides, cytoplasm just enlarges=multinucleated cellsbonus
What is the normal platelet count?
150,000-400,000/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 square=0.1mm3
1: 100 dilution
0. 1/100=1,000
so: # of cells x 1000
What criteria are used to estimate platelets in a PBS?
look at ten fields, 7-22 average which is adequate
30 - increase
5 - decrease
pale blue remnants of RNA
Dohle bodies
blue/black cytoplasm granules
toxic granulation
What do doctors use differentials for?
to diagnose disease
overall health picture
monitor therapy
reddish-blue in blast inclusion
aver rod
found in blasts
