Hematology Exam 1 Flashcards
Leukopenia
decreased WBC count
Leukocytosis
Increased WBC count
Leukemia
Uncontrolled proliferation of a clone of malignant WBCs
Neutrophilia
Increased neutrophils, often signals bacterial infection
Neutropenia
decreased neutrophils, many causes including viral infections or certain medications
thrombocytes
platelets
leukocytes
WBC
erythrocytes
RBC
Most common hematology test ordered
CBC
Plasma
The liquid portion of blood that provides coagulation enzymes
RBC count diluent used and dilution factor
Normal saline used at a 1:200 dilution
Anemia
loss of oxygen carrying capacity of RBC, often due to decreased RBC or decreased Hb
Polycythemia
increased RBC count, leads to hyperviscosity
Description of hemoglobin measurement (what reagent is used, what type of blood is used, how does the test work)
Drabkin’s reagent used (potassium cyanide and potassium ferricyanide) with whole blood.
Hemoglobin is converted to cyanmethemoglobin and absorbance is measured at 540nm on spec, color intensity compared to a standard and converted to a hemoglobin concentration
Hematocrit
%RBC in whole blood
How to perform a manual hematocrit
Put blood in capillary tube, centrifuge, measure column of RBCs and divide by total length (RBCs + plasma)
Hematocrit = RBC/Whole Blood
Function of erythrocytes
Biconcave cells filled with hemoglobin which transports O2 and CO2
Mean Cell Volume (MCV)
reflects RBC size (fL)
Mean cell hemoglobin (MCH)
mass of hemoglobin per cell (pg)
Mean cell hemoglobin concentration (MCHC)
reflects RBC staining intensity and amount of central pallor (g/dL)
RBC distribution width (RDW)
degree of variation in RBC volume (%)
high variation = increased RDW
low variation = decreased RDW
Reticulocytes (AKA polychromatic erythrocytes)
large, immature RBC released from bone marrow that stain slightly blue-gray
What does increased reticulocytes tell you?
Indicates the bone marrow responding to anemia or decreased oxygen carrying capacity (bone marrow is trying to increase RBC count)
Manual reticulocyte procedure
Counting reticulocytes by microscopy - reticulocytes will have a presence of RNA in the cell and will stain blue/gray on a Wright’s blood smear
Function of WBC
protecting host from infection
Manual WBC count diluent and dilution
Diluent - dilute acid solution
Dilution - 1:20
Neutrophils - function and structure
phagocytic cells that engulf and destroy bacteria
multi-lobed nucleus
band neutrophils vs segmented neutrophils
band neutrophils are less mature and have a nucleus in a U or S shape
segmented neutrophils are mature phagocytes and have a multi lobed nucleus
what is a “left shift”
increased band on band neutrophils that indicates a bacterial infection
eosinophils - function and structure
immune system regulation - associated with allergic response or parasitic infection
bright orange/red cytoplasmic granules
eosinophilia
increased eosinophils (allergic response or parasitic infection)
basophils - structure and what does basophilia indicate
basophils have dark purple irregular granules that obscure the nucleus
basophilia indicates hematologic disease
(RARE)
lymphocytes - structure and function
large and round nucleus, very thin rim of nongranular cytoplasm.
make antibodies and fight viral infections
lymphocytosis
increased lymphocyte count, associated with viral infectioons
lymphopenia
decreased lymphocytes, associated with drug therapy or immunodeficiency
monocytes - structure and function
immature macrophage, identifies and phagocytizes foreign particles, mounts immune response.
“ground glass” appearance with indented nucleus
monocytosis
increase monocytes associated with inflammation or certain infections
function of platelets
trigger clot formation, major cell controlling hemostasis
cell description of a platelet
round/oval, anucleate, slightly granular
rbc description
anucleate, biconcave, discoid cells filled with Hgb
what process is used for manual platelet count?
phase microscopy
Order of most common white blood cells to least common
neutrophils, lymphocytes, monocytes, eosinophils, basophils
Do males or females have a higher CBC reference range? Why?
Males will have a higher reference range due to having testosterone and more muscle mass
QA vs QC
QC is more of the “analytical” quality control (measures that are included during the process to ensure the test is working properly and results are valid and reproducible)
QA is more of the “post- and pre-analytical” quality control (ensures final results are accurate)
how to calculate SD when given the variance
the SD is the square root of the variance
How to calculate CV% (coefficient of variation)
CV% = (standard deviation/mean) x 100
How to determine 95.5% confidence interval
95.5% CI = mean +/- 2 SD
precision vs accuracy
accuracy - how close a measurement is to the true/expected value
precision - how close measurements of the same item are to each other (reproducibility)
Frequency Distribution Graph - accuracy and precision
Skinny curves are precise
Fat curves are less precise
What do you do if an assay result is out of linearity (too high)?
Patient results above linearity must be diluted and reassayed
What does a Levy-Jennings chart show?
displays each data point in comparison with the mean and standard deviations
Westgard Rules - 1 3s
one control value is outside the +/- SD limit
Westgard rules - 2 2s
Two control values are outside the +/- 2 SD limit
Westgard rules - R4s
Two consecutive control values within a run are >4 SD apart (one is +2 SD and one is -2 SD)
Westgard Rules - 41s
four consecutive control values within a run exceed the mean by +/- 1 SD
Westgard Rules - 10x
“shift” series of 10 consecutive control values are on one side of the mean
Westgard rules - 7T
“trend” series of 7 control values trend in a constant up/down direction
Delta check
compares current analyte results with the most recent previous result on the same patient
- a flag will occur if the difference between the two results is too high (20% deviation)
PPV formula - what does it tell us?
(TP/TP + FP) x 100
PPV tells us the probability that a patient with a positive result actually has the disease
NPV formula - what does it tell us?
(TN/TN+FN) x 100
NPV tells us the probability that a patient with a negative result actually does not have the disease
Euchromatin
uncondensed genetically active area of the nucleus where DNA transcription occurs
Heterochromatin
condensed/clumped transcriptionally inactive area of the nucleus
Which organelle has this function?
Modifies and packages macromolecules for other organelles and for secretion
Golgi apparatus
Which organelle has this function?
Synthesizes proteins
Ribosomes
Which organelle has this function?
Synthesizes phospholipids and steroid, detoxifies drugs, stores calcium
SER
Which organelle has this function?
Synthesizes membrane bound and secreted proteins
RER
Which organelle has this function?
Physical barrier for cell, facilitates and restricts interchange of substances with environment, maintains electrochemical gradient
Plasma membrane
Which organelle has this function?
Controls cell division and functions, contains genetic code
Nucleus
Which organelle has this function?
Synthesizes ribosomal RNA, assembles ribosome subunits
Nucleolus
Which organelle has this function?
Produces most of the ATP for the cell
Mitochondria
Which organelle has this function?
Contains hydrolytic enzymes that degrade unwanted material in the cell
Lysosomes
Which organelle has this function?
Provides strong structural support
Intermediate Filaments
Which organelle has this function?
Supports cytoskeleton and motility
Microfilaments
Which organelle has this function?
Contains centrioles that serve as insertion points for mitotic spindle fibers
Centrosome
Which organelle has this function?
Maintains cell shape, involved in cell and organelle motility and the mitotic process
Microtubules
Phospholipids found on the inner layer of the membrane
phosphatidyl serine and phosphatidylethanolamine
Phospholipids found on the outer layer of the membrane
spingomyelin and phosphatidylcholine
where are cisternae found?
on golgi apparatus
where are cristae found?
on inner membrane of mitochondria
4 stages of the cell cycle and what is occurring
- G1 phase (gap 1 phase) - cell growth
- S phase - DNA synthesis and replication
- G2 phase (gap 2 phase) - DNA checked for proper replication and damage
- M phase - mitosis (division of chromosomes into 2 daughter cells)
What is G zero phase?
quiescence, cell is not actively in the cell cycle
Interphase includes which stages of the cell cycle?
G1, S phase, and G2
prophase
chromosomes condense, mitotic spindles appear
prometaphase
nuclear envelope disappears, centrosomes move to opposite poles, sister chromatids attach to spindle fibers
metaphase
sister chromatids align on the mitotic spindle fibers
anaphase
sister chromatids separate and move toward separate poles
telophase
nuclear membrane reassembles around each set of chromosomes, mitotic spindles disappear
cytokinesis
cell divides into 2 identical daughter cells
necrosis vs apoptosis
necrosis - cell death due to external injury to cells (pathologic)
apoptosis - self-inflicted cell death due to activation signals within the cell (physiologic)
When does hematopoiesis begin? Where?
19th day of embryonic trimester. It occurs in the yolk sac
When does hematopoiesis occur in the liver?
5-7 weeks gestation
When does hematopoiesis occur in the bone marrow?
It starts at the end of the first trimester (4th month) until the 5th month of fetal development. It then occurs in the bone marrow until adulthood.
Where would hematopoiesis occur in a 10 year old? A 60 year old? 8th month of gestation? 20th day of gestation? 3rd month of gestation?
Bone marrow Bone marrow Bone marrow Yolk sac Liver
Red marrow
hematopoietically active marrow composed of developing blood cells
Yellow marrow
Hematopoetically inactive marrow composed of adipocytes
Broad, flat cells that form a continuous layer along the inner surface of arteries/veins/vascular sinuses
Endothelial Cells
Large cells with a vacuole that play a role in regulating volume of marrow in which active hematopoiesis occurs, also secrete cytokines and growth factors
Adipocytes
Retrogression
The replacement of active red marrow with inactive yellow marrow
Function in phagocytosis and secrete cytokines that regulate hematopoiesis
Macrophage
bone-forming cells
osteoblasts
bone-resorbing cells
osteoclasts
secrete extracellular matrix to anchor developing hematopoietic cells in the bone cavity
Reticular adventitial cells
Extramedullary hematopoiesis + where does it take place
Formation and activation of RBC outside of the bone marrow in response to infection ; occurs in the liver
What organ functions to filter circulating blood?
Spleen
What are the spleen’s 2 methods for removing old/abnormal RBC from circulation?
Culling and pitting
What organ is the major site of hematopoiesis during the second trimester?
Liver
What organ synthesizes and degrades proteins, synthesizes coag factors, is involved in drug and toxin clearance, and degrades Hgb?
Liver
Function of the lymph nodes?
Contain lymph which is involved in the initiation of immune response and filters particulate matter
Function of the thymus?
Site of maturation of T-cell progenitors
T/F: The thymus gets smaller as we age.
True
Splenomegaly
enlarged spleen
Splenectomy
Removal of the spleen
Hypersplenism
enlargement of the spleen resulting in pancytopenia despite a hyperactive blood marrow
HSCs
capable of self-renewal and can give rise to any type of cell
progenitor cells
differentiate into many types of cells
precursor cells
can only differentiate into a particular type of cell
Morphological changes in maturing hematopoietic stem cells
Decreased volume, decreased N:C ratio, loss of nucleoli, condensed chromatin, decreased basophilia, increase in cytoplasm
