Lecture 3 - Evaluation of RBC Flashcards
RBC come from the BM in __
long bones (humerus, femur, some wrist and flat bones)
4 Organs important for making RBC
- BM
- Kidney (Erythropoietin)
- Liver (Iron)
- Adrenal Glands, thyroid glands, pituitary, gonads (glucocoricoids, androgens, thyroxin) also help stimulate BM to make RBC precursors
__ maturation occurs in the BM
parametal (one big cell divides into 6)
RBC go to the __ to be recycled by macrophages
spleen
__ and __ go to the BM to stimulate erythropoiesis
erythropoietin and other hormones, iron
lifespan of a RBC
100days
__ contains 3 major pools - RBC precursors (BM), blood RBCs, and Splenic RBCs
erythron
After BM is stimulated by EPO, CFU-E differentiate into __ and proliferate via mitosis and mature until RBC are formed
rubriblasts
note: CFU-E = colongy forming unit erythroid cells
After release to the blood RBC circulate in the vascular system to
transport O2 to tissues
A resrve pool of RBC is sequestered in the __ of most mammals
spleen
Old (senescent) RBC are destroyed by macs in solid organs like
spleen and liver
How RBC bring CO2 back to lungs
carbonic anhydrase - increases CO2 carrying capacity by 17 fold
__ increases O2 carrying capacity of blood by 70x that of plasma
hemogloben
How is CO2 transported away from tissues
bicarbonate (70%), CA groups on Hb/RBC (25%), dissolved (5%)
3 functions of RBC
- O2 to tissues
- CO2 from tissues
- buffering of H+
__ is the major protein buffer in blood for both respiratory and metabolic acids
hemoglobin
Hb buffers effects of Carbonic acid and allwos for the transport of
CO2
Morphology of RBC in most mammal species
biconcaved disc, prominent central pallor, little anisocytosis (size difference)
A few __ RBC can be normal
polychromatophil
Cat and horse RBCs
less central palar, smaller, rouleux (protein coating)
Camels RBC
Ovalecytes or olipticytes
what values can you get from a microcentrifuge and refractometer
PCV, TP
What 6 values can you get from an automated hematology analyzer
RBC count, Hg concentration, Hct, MCV, MCHC, RDW (Red cell distribution width)
what is in the buffy coat
platelets and WBCs
neonates have __ PCV and plasma proteins
lower
note: there is also species variation in PCV
equines and ruminants may have __ plasma normally due to diet
yellow (normal, not icterus)
PCV is normally roughly between
30-50% depending on species and age
plasma color in dogs and cats should be
clear/colorless
manual count in mammals use a __ (old school before analyzers), in non-mammals
hemacytometer
note: non-mammals use natt-herricks stain and just count WBC
most common way clinics count blood cells is
automated hematology analyzers (impedence coutner, laser flow cytometry, or a blend of both)
how do automated analyzers assess the QUANTITY of RBCs
- RBC count (measured)
- Hgb concentration (measured)
- Hct % (CALCULATED)
what is the calculated version of the spun PCV given by a automated analyzer
Hematocrit % (HCT)
How do automated analyzers assess the QUALITY of RBCs
- MCV (mean cell volume/RBC size, measured)
- RDW (red cell distribution width/size variation of RBC, measured)
- MCHC (mean cell hb concentration/Hb inside RBC, CALCULATED)
What quality of RBC is calculated? quantity calculated?
MCHC. HCT
__ is the average size of RBC
MCV - mean cell volume (quality)
__ is the size variation of RBC
RDW - red cell distribution width (quality)
__ is the Hb within a RBC
MCHC - mean cell hb concentration (calculated quality)
What 3 values from an automated machine always be consistently normal, increased or decreased at the same time (or else may have issue with machine)?
PCV, Hgb, Hct (MCV and/or MCHC can vary)
RBC count is the count of how many RBC there are per __
microliter
how does the macine count Hb concentration
lyses RBCs to release Hb uses light absorbance/wavelengths to correspon to Hgb
__ can falsely increase Hgb concentration
lipemia
Hgb concentration x 3 =
PCV%
__ and __ measurements reflect the quantity/# of RBCs in the blood
RBC count and Hgb concentration
terms used to describe the MCV that aid in dz classification
Macrocytic, normocytic, microcytic
when RBC size is more variable than normal, the RDW __
increases = check blood film for anisocytosis
note: RDW = SD/MCV
In an animal with a regenerative anemia the RDW would be
increased/wide due to large immature RBCs (polychromatophils) released by BM
The spun PCV and calculated HCT should be roughtly the same, within __%
3
If PCV and HCT are not the same what should you use
properly spun PCV over calculated HCT
__ can be made false when certain dz are present like autoagglutination
HCT (it is a calculation, not a direct measurement like spun PCV)
What does the machine use to calculate HCT
RBC count and MCV
HCT = RBC count x MCV / 10
what words are used to describe MCHC variations
hyperchromic, normochromic, hypochromic (rem hgb makes the cell look red)
When is a TRUE hypochromasia/decreased MCHC seen?
Fe deficiency anemia, RBC actually have less Hb and on blood film the central palar will be increased
What is a non true hypchromasia/decreased MCHC
BM makes lots of new RBC due to anemia, RBC do not have all their Hb yet = hypochromic, but not so on blood film.
__ is essentially always an artifact due to hemolysis or interference with hgb measurements (lipemia, heinz bodies, elevated WBC)
Increased MCHC or HYPERchromasia
__ are denatured Hgb that sticks to the inside of the RBC due to oxidative damage (onions, garlic can casue)
Heinz bodies
If you have an elevated PCV and TP what should you check
If it’s an artifact ie. if the animal recently exercised (sweat, lose fluids, hemoconcentration increases)
increased PCV and TP is hallmark of
dehydration (fluid component of blood reduced - RBC and proteins concentrated)
Increase in PCV due to dehydration is termed __ and increased TP due to dehydration is termed __
relative erythrocytosis (polycythemia), hyperproteinemia
If take a sample from a horse post exercise and the PCV is normal but the TP is high, what do you expect?
Anemia! (both values should be high, hemoconcentration due to dehydration is masking the anemia in this horse)
