3. • Definition :
Leuokopoiesis is the process in which white blood cells are
formed.
It includes : 1. Granulopoiesis.
2. Lymphopoiesis.
The granulocytic elements of the bone marrow may be divided
into :-
1-Mitotic stage
2-Maturation stage
• .
4. • Regulation :
Leuokopoiesis is stimulated by :
- Interleukins(IL).
- Colony-Stimulating Factors(CSF)
• These IL and CSF are released from
macrophages and T lymphocytes that are
present in B.M. microenvironment or at site of
inflammation.
5. •CFU-GEMM (colony forming unit granulocyte erythroid monocyte megacryocyte).
•CFU-GM(colony forming unit granulocyte monocyte).
6. . Granulopoiesis
1
• Definition:
Is the process that includes production and maturation of
granulocytes (neutrophile,eosinophile,basophile).
Myeloblast
Promyelocyte
Myelocyte
Metamyelocyte
Band Neutrophil
Segmented Neutrophil
Eosinophil
Basophile
7. Mitotic pool
Myeloblast
• Most undifferentiated cell identified in development sequence.
• Size : (15-22 µm in diameter) round in shape
• Nucleus: large and round with (2-5) nucleoli(open chromatin).
• Cytoplasm: deep blue without granules.
• Normally not found in PB.
8. Promyelocyte
• Size: slightly larger than myeloblast (15 - 25 µm in diameter)
• Nucleus: range in shape from round to oval and are
usually eccentric with slight chromatin condensation & may
contain nucleolus (it begins to fade).
• Cytoplasm: less basophilic with many azurophilic
(primary) granules that contains MPO .
9. Myelocyte
• Size: (12-18 µm in diameter)
• Nucleus: eccentric and round without nucleoli
also chromatin clumping is observed.
• Cytoplasm: contains both primary and secondary granules.
• In this stage the specific granules appear for the first time
10. Maturation pool
• No mitosis take place in this stage
• Metamyelocyte
• Size :- about 15 µm
• Nucleus: Kidney-shaped without nucleoli.
chromatin increase in condensation.
• Cytoplasm: pink blue in colour contains primary, secondary and
tertiary granules.
11. Band (Nonsegmented) Cell(stab
cell )
• Size : 14 µm in diameter.
• Nucleus: U-shaped without nucleoli and
chromatin is highly condensed.
• Cytoplasm: secondary granules are predominant.
• 0-6% of WBCs is normal in PB.
12. Segmented Neutrophil
• Size : (10-15 µm) in diameter.
• Nucleus : 2-5 lobes joined by thin strand of chromatin and
it is deep purpish blue in colour.
the nucleus is easily deformable due to the active motility of
the cell (polymorphnuclear-many shaped nucleus)
• Cytoplasm: light-grey to pink cytoplasm containing very
fine granules(primary and secondary).
13. Eosinophil Maturation
the same maturation phenomena as neutrophils, but with different
specific granules that are red in colour (contains basic proteins)and
are first seen in myelocyte stage .
Develop from (CFU-GEMM) into a stem cell specific for eosinophil
(CFU-Eo) under stimulation of (IL-3) & (GM-CSF)
then into (myeloblast,promyelocyte) similar(indistinguishable)to
that seen in neutrophil under stimulation of (IL-5) and (GM-CSF).
In myelocyte stage ,eosinophilic specific granules start to appear
and this stage is distinguishable from neutrophile line.
Then it enters metamyelocyte stage and band stage to become
mature eosinophil
14. Mature Eosinophil
• Size :(12-15 µm) in diameter.
• Nucleus is biloped.
• Cytoplasm contains large red granules .
15. Basophil Maturation
• identical maturations tages to the neutrophil. The
characteristic black/purple granules start to appear at
the myelocyte stage.
• Basophil granules contains mainly Histamin and
Heparin.
• Stimulated by (IL-3 and IL-4).
18. Macrophage
• When monocyte responds to chemotaxis(bacterial
endotoxin),it enlarges and becomes highly motile leaving the
blood to enter tissue(site of infection) differentiate to
macrophage in response to local conditions and factors.
• Size: 15 to 80 μm in diameter
• Nucleus: egg shaped or may be indented or elongated.
• Cytoplasm: cytoplasm is sky-blue and contains coarse, azure
granules and vacuoles
19. Lymphopoiesis
• Is development and maturation of
lymphocytes in
1.primary lymphoid organs: Thymus and B.M
2.Secondary lymphoid organs: spleen, lymph
nodes, tonsils and other lymphoid tissue.
• CFU-L is derived from hematopoietic stem cell
under stimulation with (IL6,IL1,CSF).
20. :
Lymphocyte Maturation
1. Lymphoblast
• Size: (10-18 μm in diameter)
• Nucleus: largeand round with 1- nucleoli
nuclear chromati is thin and not clumped.
• Cytoplasm: basophilic without granules.
• Normally not seen in PB.
