Proliferation
Stage
Nucleus
Cytoplasm
Pronormoblast
(Rubriblast)
(N:C ratio of 8:1)
● round to
oval,
containing
one or two
nucleoli.
● The purple
red chromatin
is open and
contains few,
if any,fine
clumps.
Dark Blue .
● Pronormoblas
ts may show
small tufts of
irregular
cytoplasm
along the
periphery of
the
membrane.
Division
●
●
Undergoes
mitosis and
gives rise to
two daughter
pronormobla
sts
More than one
division is
possible
before
maturation
into basophilic
normoblasts.
Location
present only in the
bone marrow in
healthy states.
Cellular Activity
●
●
●
Basophilic
Normoblast
(Prorubricyte)
The chromatin begins
to condense,
● revealing
clumps along
the periphery
of the nuclear
membrane
and a few in
the interior.
● As the
chromatin
condenses,
the
parachromati
n areas
become larger
and sharper
N:C ratio
When stained, the
cytoplasm may be a
deeper, richer blue
than in the
pronormoblast—hence
the name basophilic
for this stage
Undergoes mitosis,
giving rise to two
daughter cells.
Present only in the
bone marrow in
healthy states
Begins to
accumulate
the
components
necessary for
hemoglobin
production
The proteins
and enzymes
necessary for
iron uptake
and
protoporphyrin
synthesis are
produced
Globin
production
begins.
Detectable
hemoglobin
synthesis occurs,
● but the many
cytoplasmic
organelles,
including
ribosomes
and a
substantial
amount of
messenger
ribonucleic
acid
(RNA;chiefly
for
hemoglobin
production),
completely
Length of Time in
This Stage
This stage lasts slightly
more than 24 hours
This stage lasts slightly
more than 24 hours
●
●
decreases to
about 6:1.
The chromatin
stains deep
purple-red.
Nucleoli
present but
disappear
later
mask the
minute
amount of
hemoglobin
pigmentation.
Polychromatic
(Polychromatophi
lic) Normoblast
(Rubricyte)
The chromatin pattern
varies but becomes
condensed by the end.
The condensation of
chromatin reduces the
diameter of the nucleus
considerably, so the
N:C ratio 4:1 to about
1:1. Notably, no
nucleoli are present.
First stage in which
the pink color
associated with stained
hemoglobin can be
seen.. The color
produced is a mixture
of pink and blue,
resulting in a murky
gray-blue.
polychromatophilic
means “many color
loving.”
ORTHOCHROMIC
NORMOBLAST
(Metarubricyte)
Completely condensed
(i.e., pyknotic)
As a result, the N:C
ratio 1:2.
Increase
in
the
salmon-pink
color.
Division. not capable of
division due to the
condensation of the
chromatin.
Last stage in which the
cell is capable of
undergoing mitosis
Present only in the
bone marrow in
healthy states
Hemoglobin synthesis
increases, begins to be
visible in the color of
the cytoplasm. The
progressive
condensation of the
nucleus and
disappearance of
nucleoli are evidence
of progressive decline
in transcription of
(DNA).
Present only in the
bone
marrow
in
healthy states
Hemoglobin production
continues Late in this
stage, the nucleus is
ejected from the cell.
loss of vimentin, a
protein responsible for
holding organelles in
proper location in the
cytoplasm, is probably
important
in
the
movement
of
the
nucleus to the cell
periphery.
The
enveloped
extruded
nucleus
is
then
engulfed
by
bone
marrow macrophages.
The
macrophages
recognize
phosphatidylserine on
This stage lasts
approximately 30
hours
This stage lasts
approximately 48
hours
its surface as an “eat
me” flag. Often, small
fragments of nucleus
are left behind if the
projection is pinched off
before
the
entire
nucleus is enveloped
and
are
called
Howell-Jolly
bodies
when
seen
in
peripheral blood cells.
Polychromatic
(Polychromatophi
lic)
Erythrocyte or
Reticulocyte
There is no nucleus
By the end of the
polychromatic
erythrocyte stage, the
cell is the same color
as a mature RBC,
salmon pink. It remains
larger than a mature
cell, however
Cannot divide
The polychromatic
erythrocyte resides in
the bone marrow for 1
day or longer
Complete production of
hemoglobin can be
visualized with a vital
stain such as new
methylene blue, cells
are stained while alive
in suspension (i.e.,
vital), before the film is
made . The residual
ribosomes appear as a
mesh of small blue
strands, a reticulum, or,
when more fully
digested, merely blue
dots. When so stained,
the polychromatic
erythrocyte is called a
reticulocyte
Erythrocyte
There is no nucleus
The mature circulating
erythrocyte is a
biconcave disc
measuring 7 to 8 mm
in diameter, with a
thickness of about 1.5
to 2.5 mm. salmon
pink-staining cell with
a central pale area The
central pallor is about
one third the diameter
of the cell.
Cannot divide
Mature RBCs remain
active in the circulation
for approximately
120days
The interior of the
erythrocyte contains
mostly hemoglobin, the
oxygen-carrying
component. The cell’s
main function of
oxygen delivery
throughout the body
requires a membrane
that is flexible and
deformable
Deformability is crucial
for RBCs to enter and
subsequently remain in
the circulation
Remains a
polychromatic
erythrocyte for about 3
days, with the first 2
days spent in the
marrow and the third
spent in the peripheral
blood
STAGE
NUCLEUS
Myeloblasts
Type 1
-
high nucleus-to-cytoplasm (N:C)
ratio of 8:1 to 4:1 (the nucleus
occupies most of the cell, with
very little cytoplasm)
Nucleoli: 2 - 4
Chromatin: Fine Nuclear Chromatin
______________________
Type 3
-
Size:
N:C:
Promyelocytes
CYTOPLASM
DIVISION
Type 1
slightly basophilic cytoplasm
Inclusion: Auer rods
Granules: None
Amount: Scanty
Color: Medium blue
------------------------------------Type 2
Granules: Primary Azurophilic Granules
Rare in normal bone marrows, but
can be seen in certain types of
acute myeloid leukemias
Chromatin: Darker
------------------------------------Type 3
Shape: Oval or Round, eccentric
Nucleoli: 1-5
Chromatin: Smooth; Clumping may be
visible (heterochromatin)
Evenly basophilic
Inclusion: None
Granules: Heavy, Nonspecific, full of
Primary Azurophilic Granules
Amount: Slightly Increased
Color: Moderate blue
Mitosis
Shape: Oval or Indented
Nucleoli: Variable
Chromatin: Slightly clumped
Considerable
HETEROCHROMATIN
Inclusion: None
Granules: Fine, Specific
Amount: Moderate
Color: Blue-pink
Grainy pale cytoplasm
Decrease of primary granules
production
begins to manufacture secondary
(specific) neutrophil granules.
Grainy Pale Pink Cytoplasm
(representing the presence of
secondary neutrophil Granules)
Mitosis
Final stage
Shape: Indented (Kidney bean / Peanut
shaped)
Nucleoli: None
Chromatin: Clumped
Major morphological change is the
change of shape
Inclusion: None
Granules: Fine, Specific
Amount: Moderate
Color: Pink
Synthesis of tertiary granules
(GELATINASE GRANULES)
-
More purple
Size:
N:C:
Neutrophil Myelocytes
Size:
N:C:
Neutrophil Metamyelocytes
Size:
N:C:
-
Neutrophil Bands
Size:
N:C:
Neutrophil Segmented
Size:
N:C:
Shape: Elongated or Curved
Nucleoli: None
Chromatin: Very Clumped (highly)
Inclusion: None
Granules: Fine, Specific
Amount: Abundant
Color: Pink
SECRETORY GRANULES may
begin to form
Shape: Distinct Lobes 2-5
Nucleoli: None
Chromatin: Densely packed
Inclusion: None
Granules: Fine, Specific
Amount: Abundant
Color: Pink