Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Clinical Pathology > Hematology Instruments & Blood Cell Measurements (2) > Flashcards

Hematology Instruments & Blood Cell Measurements (2) Flashcards

Dr. Harvey

1
Q

What are the main categories of a CBC?

A

erythrocyte parameters
leukocyte counts
platelets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two hematology instruments - types of technology?

A

electrical impedance method
laser flow cytometry method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the impedance method

A

blood cells are diluted in saline and flow across an aperture using electric charge

arranged in single file, and the degree of resistance tells you the volume of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What variables does the impedance method use in hematology?

A

resistance

cell volume

the change in resistance is PROPORTIONAL to cell volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Cats have the biggest ____ of any domestic animals regarding hematology

A

platelets

cannot be read using impedance method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of impedance instruments?

A

count and size cells

providing cell volume distributions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the limitations of impedance instruments?

A

cannot determine the intracellular contents of the cells

cannot do platelet counts accurately in cats

limited accuracy but excellent precision

cannot perform reticulocyte counts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the parts of laser flow cytometry? What do they show?

A

forward scatter - size
side scatter - complexity/granularity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The forward scatter measures the cell’s ____

A

shadow

a relative indicator of the cell’s size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

List a type of cell that has high amounts of side scatter

A

neutrophils (granulocytes) - with their multilobed nucleus and granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

List a type of cell that has low amounts of side scatter

A

lymphocytes - have a high nucleus to cytoplasm ratio and scant cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Laser flow cytometry counts and classifies cells based on ___

A

extinction of light and scattered light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What can laser flow cytometry count that impedance cannot?

A

reticulocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do automated cell counters calculate hematocrit?

A

from the mean cell volume (MCV) and RBC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do you determine hemoglobin?

A

spectrophotometry

using a sodium lauryl sulfate reagent

measure absorbance and protein conc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the mean cell volume MCV?

A

average volume of a single erythrocyte, measured in femtoliters

determined directly in hematology analyzers

17
Q

What is mean cell hemoglobin, or MCH?

A

average amount of hemoglobin in a single erythrocyte (picogram = 10^-12 g)

18
Q

What does MCH generally correlate directly with?

A

mean cell volume (MCV) - because of changes in erythrocyte size

19
Q

How is MCHC (%) reported?

A

as g/dL of packed erythrocytes NOT g/dL whole blood

19
Q

What is MCHC?

A

mean cell hemoglobin concentration

20
Q

What is RDW?

A

red cell distribution width

uses standard deviation of erythrocyte volumes / MCV x 100

remember Gaussian curve and sd units

21
Q

What is the significance of RDW?

A

it is an electronic measure of anisocytosis

22
Q

What is spuriously increased RDW?

A

erythrocyte agglutination

platelets counted in erythrocyte histogram of severely anemic patients

23
Q

Only ________ reticulocytes are counted in most instruments

A

aggregate

24
Q

What are spurious reticulocytosis?

A

Howell-jolly bodies
large immature bodies or platelet clumps
autofluorescence

25
Q

Platelet aggregates can result in _____

A

false thrombocytopenia (low platelets), especially in cats

26
Q

What is MPV?

A

mean platelet volume

27
Q

What is an error in blood cell measurements regarding erythrocytes? How do you correct it?

A

nucleated erythrocytes in blood - counted as leukocytes by manual and most automated cell counters

calculate corrected total leukocyte count before calculating absolute differential leukocyte counts

28
Q

What are some sample errors in blood cell measurements?

A

not going to be asked specifically on exam I dont think

also hemolysis, lipemia, Heinz bodies

Clinical Pathology (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions