Structure and Function of RBC's Flashcards
3 cell types in blood
RBCs
platelets
Leukocytes
normal RBC count for Male/Female
> 4.7-6.1 x 10^6/microliter
>4.2-5.4
Normal Hgb for male/female
> 14-18
>12-16
Normal Hct for male/female
> 42-52 male
>37-47 female
MCV < 80
microcytic
MCV >100
macrocytic
MCV 80-100
normocytic
MCV<70
thalassemia
definition of anemia
reduction in the mass of RBC’s
Hematocrit=
Total RBC count x MCV
Normal hematocrit shortcut
3 x Hgb
differnces in shape
anisocytosis
differences in size
poikilocytosis
normal RDW range
11.5-14.5%
How to keep blood sample from clotting
EDTA (lavender top)
Stain used in periph. smear
“wright-giemsa”
EOSIN CHARACTERISTICS
**STAINS HEMOGLOBIN** >ACIDIC/AROMATIC >STAINS HYDROPHOBIC BASIC MACROMOLECULES >soluble in ethanol >insoluble in water
CELL with clearly defined pink cytoplasmic granules
>segmented nucleus
EOSIN-ophil
Characters of Methylene Blue stains
> BINDS NUCLEIC ACIDS (HYDROPHOBIC ACIDS)
aromatic/basic
positively charged
SOLUBLE IN WATER OR METHANOL
RELATED TO TISSUE MAST CELLS
basophils
list cells in order of their prevalence
neutrophils (40-70%), lymphocytes(20-30%), monocytes (3-8%), eosinophils (5%), basophils (1%)
cells that bind little eosin of methylene blue
neutrophils
describe neutrophil appearance
neutral cells with salmon pink cytoplasmic granules
SEGMENTED NUCLEI
LIFESPAN OF NEUTROPHILS
1 DAY
NEUTROPHILS INCREASE IN RESPONSE TO
BACTERIAL INFECTIONS
*10 FOLD
Weapons employed by neutrophils during bacterial infections
- phagocytosis
- degranulation–>so will have granules
- Extracellular NETS
secondary neutrophil granules
salmon pink
How to separate monocytes from lymphocytes
indented “ameboid” nucleus in a mono
> lymphocyte will have a rounded nucleus
how to separate monocytes from BANDS or granulocytes
–>absence of granules in mono (but nuclei will look similar)
2 conditions under which lymphocytes increase in number
- viral syndromes
2. neoplastic events (leukemia)
life span of a lymphocyte
months-years
distribution of lymphocytes
T cells–>B cells–>NK cells
reactive lymphocytes
increase in viral syndromes
more cytoplasm, prominent nucleoli
“large granular lymphocytes”
NK and CTL’s with basophillic cytoplasmic granules
SMall fragments that lack nuclei
plastelets
(100 x more prevalent than white cell population)
*400 Billion/person
4 functions of platelets
- primary hemostatic plug
- stimulate coagulation cascade–>fibrin clot formation
- recruit fibroblasts and promote wound repair
- secrete platelet factor 4 to inactivate pathogens
- antigen presentation
platelet response in IDA
platelets increase
lifespan of platelets
9-10 days
90% of the time: reactive Left Shift indicates
bacterial infection
cells seen in a left shift
bands, metamyelocytes, myelocytes
What is toxic granulation
Increase in PRIMARY (basophillic) cytoplasmic granules in neutrophils seen in bacterial infection
primary granules/toxic granulation is only present in
early myeloid precursors in the bone marrow
eosinophils increase…
in response to allergic reactions and infection with parasites
Anion exchanger
band 3
Methemoglobin
hemoglobin with oxidized iron Fe+++ that cannot carry O2
describe the RBC antioxidant system
02 spontaneously converted to H2O2 (toxic free radical)–> converted to the inert molecule water by GSH–>to replanich GSH…NADPH is required!!!!
Mutations in anti-oxidant system results in…
bit cells–>tissue macrophages take chunks out of RBC to remove the ROS’s
enzyme required to reduce methemoglobin
hemoglobin with iron in the ferric /fe+++ state
Cytochrome B5 reductase
Cytochrome B5 reductase requires
NADH
How does free radicals affect Hgb in a RBS
oxidized Hgb molecules (oxidizes SH groups) crosslink and cause hemoglobin to denature and/or precipitate
do mature RBC’s have nucleus or mitochondria
NO
to make room for HGb and they only rely on glycolysis
Glycolysis within the RBC provides
ATP (though inneficiently) and NADH (for Cytochrome b5 reducatase)
Pentose phosphate shunt within the RBC is used for
repletion of NADPH so that the cell can replentish GSH for H2O2-H2o reaction
first enzyme in pentose phophate shunt pathway
g6pd
G6pd deficiency will show what on blood smear
bite cells and blister cells
(SH groups are cross linked and precipitate out–>tissue based macrophages remove the membrane+ cytoplasmic arease affected by the ROS
slow the process of compliment fixation on a normal RBC–>
Decay Accelerating Factor
DAF counteracts which compliment fixation process
alternative
definition of hypochromia
greater than one third of the cytoplasm on Peripheral Blood Smear is taken up by area of central pallor
Define polychromasia and when it is usually seen
Bluish tinge caused by methylene blue binding to residual RNA in a newly formed RBC
>usually seen when RAPID production of RBC’s is required–>due to rapid blood loss
Rapidly produced RBC’s are usually
biger than more mature counterparts and hypochromatic
genetic defect in hemoglobin structure
hemoglobinopathy
Heinz bodies
small clumps within the cytoplasm of an RBC that indicated oxidized and denatured hemoglobin–> LEADS TO BITE CELLS
conditions which would give you heinz bodies
- G6pd deficiency
- NADPH deficiency
- Chronic liver disease
- alpha thalassemia
Cleaved RBC’s
schistocytes
Schistocytes tell you what?
microangiopathic hemolytic anemia
*there are many things that can cause/lead to this finding
supernatant of clotted blood
serum
supernatant of unclotted blood
plasma
manual hematocrit=
RBC volume/ Total blood volume
hematology analyzer hematocrit
= MCV x TOTAl RBC count
estimate of hematocrit=
normally should be Hgb x 3
how to correct for reticulocyte count
total retic x (hct/45)
*should be less than 1.7
What methods does a hematology analyzer measure
- Spectophotometry (assesses number)
- CONDUCTIVITY-Coulter Chamber- (assesses number, COMPLEXITY and volume/size
- FLOW CYTOMETRY
Hgb concentration is measured via
spectophotometry
*add cyanide and measure % absoprtion
most reliable measure of anemia
Hgb because it is measured directly and is not dependent on two measured variables as Hct is
How are reticulocytes counted
SPECTOPHOTOMETRY
>add methylene blue–>analyzer will measure recently made (larger than usual) RBC’s containing residual RNA)
reticulocytes seen on a peripheral smear should elicit
a “polychromasia” comment
*RNA is a fine network staining blue–>reticular network
Routine CBC WILL measure…
>Hgb concentration >RBC count >MCV >RDW-->indicates anisocytosis >platelet count >MOV
Caculated value that the CBC also spits out but doesnt measure directly
hematocrit
mch (hgb/RBC)
mchc (hgb/hct)
In pt.s with anemia which value do you being with for DX
MCV
*will tell you micro vs macrocytic
A patient who for any reason is making red cells rapidly will have
increased MCV
*Macrocytic, polychromatic, reticulocytes
Coulter chamber can also count leukocytes how?
separate set of electrodes measures complexity as they pass thru aperture–>more lobulated nuclei will diff. poly’s vs. mono’s etc
flow cytometry in a CBC is used for
- -> separating out leukocyte cell populations even further than the conduction study
- ->Immature Platelet Fraction (platelets with excess RNA)
What the hematology analyzer will NOT count
>bands >blasts-->wil not catch acute leukemias >Red Cell fragments >platelet clumps *therefore these measurements require a manual differntial!!!!
bands usually charcterized as
neutrophils by most analyzers
blasts usually counted as
lymphocytes or monocytes
red cell frags usually counted as
pletelets
platelet clumps usualy counted as
not always counted and can result in artifactual thrompocytopenia
what causes hypochromia in RBC’s
lack of hemoglobin
oxidized HGhg will lead to what to peripheal smear findings
- heinz bodies
2. bit cells–>tissue macrophages take out chunks of a cell that has been damaged by ROS
polychromasia is usally seen with?
accelerated prodcution
main function of monocyte
antigen presentation to lymphocytes
eosinophils increase with
parasite infections, drugs and allergic reactions
starting point for Dx of ay increase in any cell type
reactive vs. neoplastic
