Eosinophil
Peripheral
Blood
Erythrocytes = RBCs
• NO NUCLEUS
• Contain hemoglobin
Platelets
Leukocytes = WBCs
• Granulocytes
• Neutrophils = PMNs = “polys”
• Eosinophils = “eos”
• Basophils = “basos”
• Agranulocytes
• Lymphocytes = T and B cells
• B cells  plasma cells
• Monocytes  Macrophages (MΦ)
Granulocytes
PMN
Eos
PMN
Baso
Neutrophils
• Numerous
• Multilobed nucleus
• Azurophilic & Specific
granules
• Phagocytose bacteria
Basophils
• Rare!
• Lobulated nucleus
often obscured by
granules
• Dark Blue Granules
• Hydrolytic enzymes,
heparin sulfate,
histamine, SRS
• Function
• Role in hypersensitivity
and anaphylaxis
Eosinophils
• Bilobed nucleus
• Bright pink Granules
• Arginine rich major
basic protein,
peroxidase,
histaminase,
arylsulfatase
• Function:
• Important in allergic
rxns, parasitic
infections, and
phagocytosis of Ab-Ag
complexes
Monocytes
• Largest WBCs in blood
smear
• Migrate through blood
to the tissues; once in
tissues they
differentiate into
phagocytes
(macrophages,
osteoclasts)
Lymphocytes
• About size of RBCs
• Function
• Adaptive immune
system
• T & B cells
Questions
Which of the below cell types would increase in number
with a bacterial infection? Viral? Parasitic?
Bone
Marrow
Smear
Erythropoesis
Proerythroblast
• Biggest in lineage
• Large central nucleus
with one or two
nucleoli
• Basophilic cytoplasm
b/c ribosomes
• Look for Golgi ghost
Basophilic Erythroblast
• Smaller than
proerythroblast
• Checkerboard nucleus
(heterochromatic)
• Intense basophilia (lots
of ribosomes!)
Proerythroblast vs Basophilic
Erythroblast
Polychromatophilic
Erythroblast
• Smaller than basophilic
erythroblast
• Smaller intensely
heterochromatic nucleus
• Purple/lilac cytoplasm mix
of basophilia from
ribosomes and growing
eosinophilia from
hemoglobin
• LAST MITOTIC STAGE!
Normoblast
• Smaller than polychromatophilic erythroblast
• Small, compact, intensely staining nucleus that is
getting ready to be extruded
• Eosinophilic cytoplasm due to abundant
hemoglobin
Reticulocyte
• Immature RBC that has
polyribosomes
• Appear as polychromatophilic erythrocyte
on blood smear
• When stained with a
special (supravital)
stain  Reticulocyte
Erythrocyte
• Smallest
• Eosinophilic due to
hemoglobin
• NO NUCLEUS!
Review
Granulopoesis
Ross
Fig 9-18
p. 235
Development
of Granulocyte
(focus on
PMN)
What are
Granulocytes?
• WBCs that contain specific granules
• Granule contents vary between cell types and
stain differently
• Neutrophils (“polys” or PMNs)
• Eosinophils
• Basophils
Trend of Development
•
•
•
Larger  smaller
Azure granules  specific granules
Round nucleus  altered shape nucleus
Granulocyte Lineage:
Myeloblast → Promyelocyte → Myelocyte →
Metamyelocyte → Band → Granulocyte
Myeloblast
Prominent
nucleoli
PROmyelocyte
• Details
• Golgi ghost
• Can’t distinguish type
of granulocyte yet
• Eccentric nucleus
• Don’t confuse with
proerythroblast or
basophilic erythroblasts
Myelocyte
• Last stage in
which mitosis
can occur
• Begin to see
who’s a
neutrophil,
who’s an
eosinophil
(who’s a
basophil)
• Golgi ghost
Neutrophilic Myelocyte vs
Eosinophilic
Myelocyte
METAmyelocyte
• nucleus changing
shape, not spherical
• No more mitosis
Band Cell
• Immature granulocyte
• Elongated nucleus of
nearly uniform width;
horseshoe/U-shaped
Finally . . .
Myeloblast – no granules
capable of
mitosis
Promyelocyte – azurophilic granules
Mylocyte – specific granules
Metamylocyte – specific granules
nucleus
changes shape
Band cell – (PMN only) specific granules
Mature Granulocyte – specific granules
Review
Compare what you
see . . .
Megakaryocyte
• Huge
• Platelets form
from
invaginations
of this
• Multilobular
nucleus
Monocyte
Don’t Worry, Be Happy!
Animations:
http://www.medtraining.org/ltac/
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