Hematology Flashcards
Normal blood separates into _____ formed elements and ____ plasma
45% formed elements; 55% plasma
Formed elements separates into (2)
Buffy coat (WBC/platelets) and RBCs
The composition of plasma is ____ water, ___ protein and ___ other solutes
90% water; 7% protein; 3% other solutes
Of all protein in plasma, what makes up the majority; what about the second highest
albumin (60%); globulins (35%)
What is the role of transient proteins in the bloodstream
No functional role; we use them as markers of damaged and dying cells
plasma vs serum
plasma: anticoagulants added; contains clotting proteins
serum: allowed to clot; clotting proteins removed
lipidemia looks
white
hemoglobinemia looks
red
bilirubinemia looks
yellow
plasma of a healthy dog and cat is
colourless to light yellow (due to bilirubin)
plasma of a healthy cow and horse is
medium yellow (due to carotenoids; horses also have a higher bilirubin concentration)
plasma of a healthy sheep and pig is
colourless
in what 2 organs is there secretion AND absorption of solutes in blood (as opposed to just outward)
kidney and liver
Most enzymes in serum are usually
found in cells and leaked out
what are examples of enzymes that are normally not in cells
clotting enzymes, lipoprotein lipase
where in the cell can enzymes be localized
cytoplasm, mitochondria, ER, intracellular granules, cell membrane
cell enzymes in what location are first to be released
cytoplasmic
cell enzymes in what location are released after minor cell injury
granule
cell enzymes in what location are released after severe insult
mitochondria
cell enzymes in what location are not soluble and only released after severe insult
membrane
ALT
alanine aminotransferase
AST
aspartate aminotransferase
SD
sorbitol dehydrogenase
LD
lactate dehydrogenase
ALP
alkaline phosphatase
GGT
gamma glutamyltransferase
CK
creatine kinase
what impacts the levels of serum in enzyme (4)
tissue concentration of that enzyme; cellular location of the enzyme; amount and severity of tissue injured; rate of removal from the serum
how are enzyme levels commonly measured in blood
kinetic assays; add substrate that changes colour in presence of the enzyme
using heparin affects the results of what assay
BUN (since heparin is often in the form of ammonium salt)
EDTA, oxalate and citrate affect the results of what assay
calcium (since they chelate calcium)
hemolysis results in increased readings for analytes, such as (4)
iron, lactate dehydrogenase, potassium, total protein
why do you fast before a blood test
lipemia alters many serum factors
what characteristics of serum enzymes make them a useful clinical marker (6)
intermediate half-life
rise specifically when tissue is injured
do not rise under normal conditions
easy to measure
tissue-specific
concentration
what is the reference interval for a serum value
value (range) of a specific enzyme in a group of clinically healthy animals of the same species
reference intervals are accurate what percentage of the time
95%
how does error relate to measuring serum
for each test ordered, the chance of a false positive increases by roughly 5% (5% for one test, 9.75% for 2 tests…)
reference values are calculated based on the mean +/- ____ SD
mean (level in the healthy population) +/- 2 SD
name 5 factors that can impact test results
age, species, stress, lipemia, hemolysis
erythrocyte appearance in mammals
anucleate and biconcave
erythrocyte appearance in reptiles and birds
nucleated and oval
hemostatic cells in birds and reptiles are called
thrombocytes
instead of neutrophils, birds and reptiles have
heterophils
what special mononuclear cell is only present in reptiles
azurophils
T/F birds have azurophils
F; only reptiles
describe the progression of sites of hematopoiesis
yolk sac -> liver -> bone marrow
what determines lineage commitment
growth factors (GFs) and colony-stimulating factors (CSFs)
what are the sites of extramedullary hematopoiesis in adults
spleen, liver
IL-3, M-CSF and GM-CSF stimulate the production of
all CFU-Gemm types (everything but lymphocytes)
IL-11 stimulates
platelets (as does thrombopoietin)
myeloblasts are the precursor to all
granulocytes
the process of erythropoiesis takes
5-6 days
describe the stepwise process of erythropoiesis
pluripotent stem cell -> CFU-gemm -> BFU-E -> rubriblast -> prorubricyte -> rubricyte -> metarubricyte -> reticulocyte -> RBC
up to what stage are RBC precursors in the proliferative pool
up to pro-rubricyte
at what stage are RBC precursors in the maturation pool
rubricyte and onwards
what are factors that can impact erythropoiesis
the right environment, factors from macrophages and lymphocytes, EPO, cell-cell interactions
how does CKD cause anemia
lack of EPO produced by diseased kidneys; diseased kidneys release toxins that negatively impact RBCs
In fetuses _____________ is released by ______________, which is catalyzed into erythropoietin by _______________
erthropoietinogen; liver; erythrogenin
In adults, _______________ is released by _________________, which is catalyzed into erythropoietin by _______________.
proerythropioetin; kidney; plasma enzyme
what is the lifespan of RBCs in dogs
100 days
how many RBCs are replaced daily (%)
1%
where are RBCs removed
spleen
what is a major factor related to death of RBCs
decrease in deformability
heme is catabolized into
iron and biliverdin
what happens to biliverdin
reduced to bilirubin and released into circulation
what happens to bilirubin once it reaches the liver
conjugated to form bilirubin-glucuronide
what happens to conjugated bilirubin
excreted into the intestine and converted to urobiliogen
what are reticulocytes
immature enucleated erythroid cells that still contain some RNA; slightly bigger than RBCs
presence of reticulocytes indicates
a productive marrow response (it has all the iron and nutrients to function adaptively)
how do reticulocytes look histologically
slightly larger and more basophilic (due to RNA)
T/F observation of reticulocytes requires methylene blue
T
with a Wright’s stain, what is observed in the presence of reticulocytes
polychromasia
polychromasia
variation in staining due to the presence of reticulocytes in blood
normocytic
normal RBC size
anisocytosis
variation in RBC size
macrocyte (macrocytic)
increased volume and diameter
microcyte (microcytic)
decreased volume and diameter
hypochromic
decreased hemoglobin content and staining
normochromic
normal staining intensity
with what condition is hypochromasia frequently seen
iron deficiency anemia
basophilic stippling
bluish inclusions in the cytoplasm
heinz bodies
refractile inclusions caused by precipitation of Hg; seen with onion toxicity
Howell-Jolly bodies
chromatin residues
acanthocyte, poikilocyte, leptocyte, spherocyte, etc.
morphological changes in the shape and size of RBCs associated with pathologic states
how is blood Hg measured
by lysing the cells in a volume of blood and then measuring the Hg chemically with a spectrophotometer (as cyanomethhemoglobin)
T/F hematocrit and PCV are interchangable terms (for this course)
T
when RBC numbers are low, PCV/Hct is
low
what is PVC/Hct
percentage of a volume of whole blood composed of RBCs in a centrifuged sample
MCV
mean corpuscular volume; average volume of each RBC
MCH
mean corpuscular Hg; average total amount of Hg in each RBC
T/F MCH measures the mean volume of Hg in each RBC
F; it measures mean total amount of Hg
MCHC
mean corpuscular Hg concentration; average concentration of Hg in each RBC
RDW
red cell distribution width; difference in size between largest and smallest RBCs in a sample; indicates increased number of reticulocytes OR smaller cells
if MCV is high, the cells are ______; if MCV is low, the cells are _______
macrocytic; microcytic
Is MCHC or MCH more useful
MCHC (corrects for size and volume differences)
if MCHC is high, the cells are _________; if MCHC is low, the cells are _________
hyperchromic; hypochromic
high RDW indicates
anisocytosis
polycythemia
increased number of RBC per ml of blood; associated with elevated PCV and Hb
what is a leukemic syndrome that causes polycythemia
polycythemia (rubra) vera
what is relative polycythemia; how can it be differentiated
polycythemia due to dehydration OR splenic contraction; if dehydrated, will also see elevated total protein
high PCV with normal protein suggests
polycythemia
high PCV with high protein suggests
dehydration
high PCV with decreased EPO suggests
polycythemia vera
high PCV with increased EPO suggests
tumor or hypoxia
causes of anemia
blood loss, iron deficiency, immune destruction, bone marrow pathologies, chronic inflammation/disease
decreased PCV with normal TP suggests
anemia
normal PCV with elevated TP may suggest
anemia with dehydration
T/F regenerative anemias have a better prognosis than non-regenerative anemias
F
what are the cytometric types of anemia
normocytic normochromic; macrocytic normochromic; macrocytic hypochromic; microcytic normochromic; microcytic hypochromic
what are the erythrokinetic types of anemia
regenerative and nonregenerative
when are regenerative anemias seen
hemolysis with recovery of the iron; single acute hemorrhage with sufficient time for a marrow response
what is always an indicator of regenerative anemia
anisocytosis and polychromasia
IMHA is a
regenerative anemia
what lab tests allow you to determine increased RBC turnover/production
reticulocyte count; bone marrow biopsy; serum unconjugated bilirubin or urine urobilinogen
causes of non-regenerative anemia
chronic or immediate blood loss (within past 24h); extra-marrow disease/deficiencies (ex. iron); intramarrow disease (ex. leukemia)
how long to platelets circulate
10 days
T/F you may likely see megakaryocytes in blood
F; RARELY ever occurs
where are megakaryocyte pools
spleen, lungs, bone marrow, liver
primary hemostasis involves ___________, secondary hemostasis involves __________, and tertiary hemostasis involves ___________
formation of the platelet plug; stabilization via fibrin clot; dissolution
what does the endothelium secrete to prevent hemostasis
prostacyclin (PGI2) and nitric oxide (NO)
with vessel injury, platelets
adhere to vWf
what do activated platelets release
ADP - attracts more platelets
serotonin - maintains vasoconstriction
TXA2 - promotes aggregation, degranulation, vasoconstriction
normal dogs have platelet counts greater than __________ and horses _________
200,000; 100,000
bleeding occurs when platelet counts are less than
30,000
coagulation enzymes commonly require (2) as cofactors
phospholipid and calcium
contact pathway is initiated by what factor
XII
tissue factor pathway is initiated by what factor
III (TF) -> IIIa
what factor causes fibrin cross-linking
XIII
what coagulation factors require gamma carboxylation by vitamin K
2, 7, 9, 10
what inhibits vitamin K (poison)
warfarin
antithrombin III inhibits factors
2, 7, 9, 10, 11, 12
T/F protein C inhibits coagulation
T
disorders with primary hemostasis manifest as ________ whereas disorder with secondary hemostasis manifest as _________
petechiae (on skin/MM); hemorrhage
ACT measures activity of
common pathway and contact pathwat
APTT measures activity of
contact pathway and common pathway
PT measures activity of
TF pathway and common pathway
where is tPA released from
endothelial cells
leukocytosis
elevated total number of WBCs
leukopenia
decreased total number of WBCs
what is the most common circulating granulocyte in dogs
neuts
what is the most common circulating agranulocyte in dogs
lymphocytes
what is the WBC equivalent of reticulocytes
band cells
what are the steps in WBC production
|myeloblast -> promyelocyte -> myelocyte -> | metamyelocyte -> band cell |
what is the normal neut lifespan
less than 24 h
in what cases do neutrophils accumulate in tissues
chronic inflammation or leukemia
what is the characteristic feature of band cells
unsegmented nuclei
a left shift indicates
infection, hypoxia, shock
what impact does the initial response have on neutrophils
decrease (increased margination and migration)
what impact does the intermediate phase have on neutrophils
increase (neutrophils in marrow reserve released)
what impact does the progressive phase have on neutrophils
increase (in marginal and circulating pools)
neutrophils usually make up ____% of circulating WBCs
50-70
where are most toxic changes observed; why do they occur
in band cells; intense stimulation of granulopoiesis with a shorter maturation window
what are toxic changes
less condensed chromatin, bluer cytoplasm (retention of RNA), doehle bodies (ribosomal protein)
stress induces decrease in the number of ________ and increase in the number of __________ and _________
lymphocytes; monocytes and neutrophils
what is the lifespan of a macrophage
months to years
T/F eosinophils can phagocytose bacteria, yeast, ab-coated RBCs, mycoplasma and mast cell granules
T
what is sometimes seen as an idiopathic infiltrate in lungs and muscle
eosinophils
glucocorticoids result in a decrease in
eosinophils
what two cell types are very similar
basophils and mast cells; both have histamine
basophils attract what cells via chemotaxis
eosinophils and neutrophils
T/F basophilia is associated with diseases that cause IgE production
T
what is associated with heartworm
basophilia
