There are three main theories of hematopoiesis or blood cell formation: monophyletic, dualistic, and polyphyletic. The monophyletic or unitary theory, first proposed over 100 years ago, suggests that all blood cells originate from a common stem cell. Stem cells are classified based on their differentiation potential as totipotent, pluripotent, multipotent, or unipotent. Hematopoiesis occurs primarily in the bone marrow and is regulated by growth factors. The process involves the proliferation, differentiation, and maturation of stem cells into the various mature blood cell types through multiple cellular stages. A complete blood count provides indicators of normal or abnormal hematopoiesis. Stem cells

1. Monophyletic theory of
hematopoiesis. Stem cells
TERESHCHENKO IRYNA
SECOND MEDICAL FACULTY, CHARLES UNIVERSITY IN PRAGUE

2. Theories of Blood Cell Formation
 Monophyletic theory  Dualistic theory  Polyphyletic theory
Also known as Unitary
Theory, first introduced by
russian histologist
A.A.Maksimov more than
100 years ago, suggest that
there is a common parent
cell of all forming elements
of blood – indifferent
mesenchymal cell, which is
able to form cells of
lymphoid, myeloid and
erythroblast line.
Dualistic theory includes
two sources of
hematopoiesis: myeloid
and lymphoid.
Proposed by:
Erlich,Schridde, O.
Naegeli
Also known as Trialistic
theory, suggest different
groups of blood cells
originate from different
stem cells. Three
systems: myeloid,
lymphoid and
reticuloendothelial.
Proposed by: L. Aschoff
Exist three theories of hematopoiesis (Blood Cell Formation), but the most
common still is Unitary (Monophyletic theory).

3. ”
“All blood elements
develop from one
origin cell – stem cell
Monophyletic theory, A. A. Maksimov
The term "stem cell” Maksimov proposed in 1908.

5. Stem Cell
Stem Cells - a cell that has the ability to continuously divide and
differentiate (develop) into various other kind(s) of cells/tissues.
 has the ability to self-support of its number;
 rarely divided; new formed elements are formed by dividing
progenitors;
 is a source of all kinds of blood cells (stem cell is pluripotent – has an
ability to develop into all kinds of cells of tissue);
 from all the cells, stem cell is most resistant to damage.

6. Classification
Totipotent stem cells
are found only in
early embryos. Each
cell can form a
complete organism.
Pluripotent stem cells
Obtained from the
inner cell mass of the
blastocyst, able to
differentiate into
almost all cells of the
three germ layers –
but not into an
embryo.
Multipotent stem cells
Found in most tissues,
can produce a limited
range of differentiated
cell lineages
appropriate to their
location (e.g.,
Hematopoietic stem
cells from the bone
marrow). Limited in
what the cells can
become.
Unipotent cells
capable of
generating only one
cell type (epidermal
stem cells, adult liver
stem cells).
Stem cells can be classified into four broad categories, based on their ability to
differentiate:
Stem Cells

7. Hemopoiesis (Hematopoiesis)
 Haematopoiesis is a process of formation of blood cellular
components. All cellular blood components are derived from
haematopoietic stem cells (HSC).
Sources of hematopoietic stem cells in human
 Umbilical Cord blood.
 Peripheral blood.
 Bone marrow

8. Hemapoiesis (Hematopoiesis)
Hemo = Hemato = Blood
Poiesis = Production
Hemopoiesis system
 Bone marrow
 Spleen
 Liver
 Thymus
 Lymph node

9. Stages of Hemopoiesis
Include:
 Proliferation (reproduction by neoplasms);
 Differentiation (sequential process of mitosis during which cells
acquire specific morpho-functional traits)
 Maturation of cells (process when the cell continues to evolve but
no longer divided)

10. DiagramofHemopoiesis

11. STEM CELLS THAT GIVES RISE TO ALL
BLOOD CELLS TYPES IS INCLUDING:
1. LYMPHOID STEM CELL (Progenitor):
 T- Cell
 B- Cell
 Natural Killer (NK-Cell)
- IS THE TYPE OF CYTOXIC LYMPHOCYTES.
2. MYELOID STEM CELL (Progenitor):
 Monocytes
 Neutrophils
 Basophils
 Eosinophils
 Erythrocytes
 Megakaryocytes - Platelets

12. Immature vs Mature cells
The immature blast cell:
 Large cell, high Nucleo-
cytoplasmic ratio
 Large nucleus, fine chromatin
& nucleoli
 Small amount of dark blue
cytoplasm
With maturation:
 Cells become smaller
 Nuclear chromatin clumps,
nucleoli disappear
 Hgb or granules appear
 N:C ratio decreases
During maturation cells changing its properties.

13. Development of erythrocyte
During development erythrocyte loses its nucleus.
Phase 1:
Ribosome synthesis
Phase 2:
Hgb accumulation
Phase 3:
Ejection of nucleus
Development pathway

14. Hemopoietic growth factors
Erythropoietin (EPO)
 produces primarily by cells in the kidney that lie between the kidney tubules
(peritubular interstitial cells)
 Control erythropoiesis - red blood cell production
 Required for a myeloid progenitor cell to become erythrocyte
Thrombopoietin ( TPO)
 Hormone produced by by the liver
 Stimulates the formation of platelets from megakaryocytes
(megakaryocytopoiesis)
A hormone-like substances (protein) that stimulate bone marrow to produce blood cell and
promote the proliferation of blood cells.

16. Classes of stem cells
By degree of maturity the cells are divided into 6 classes:
 1 class – Stem cells (Pluripotent)
 2 class – half-stem cells (Polipotent)
 3 class – Unipotent cells (give rise to only one type formed elements)
 4 class – Blasts (large cells)
 5 class - Differentiating precursors
 6 class - Mature formed elements circulating in the bloodstream

18. Bone marrow smear shows
developing cells differing in sizes,
nuclear shapes, contour and
chromatin pattern, cytoplasm for
basophilia and presence or
absence of granules. Wrights –
Giemsa x 200

19. Human bone marrow:
Neutrophilic myelocyte (h), metamyelocyte (a), and mature (e) and band (g) neutrophil. W-G x 400.
A myelocyte is a young cell of the
granulocytic series, occurring
normally in bone marrow, but not
circulating in blood (except when
caused by some disease).
Develop into neutrophil.
Neutrophils are normally found in
the bloodstream. During the
beginning (acute) phase of
inflammation, particularly as a
result of bacterial infection,
environmental exposure, and
some cancers, neutrophils are
one of the first-responders of
inflammatory cells to migrate
towards the site of inflammation.
M
N

20. DiagramofHemopoiesis

21. Human bone marrow: Very early neutrophilic promyelocyte (a) is very basophilic &
chromatophilic, proerythroblast (c). Wrights-Giemsa x 400
Promyelocyte (or
progranulocyte) is a
granulocyte precursor,
developing from the
myeloblast and developing
into the myelocyte. In the
end of the 4th phase
develop into Basophil.
Pm
Pe

22. DiagramofHemopoiesis

23. Human bone marrow: Neutrophilic metamyelocytes (f, g), mature eosinophil (h), neutrophlic myelocyte
(i), eosionophilic myelocyte (j), lymphocyte (k). W-Giemsa x 400
A metamyelocyte is a cell
undergoing granulopoiesis,
derived from a myelocyte,
and leading to a band cell.
Develop into eosinophil,
neutrophil or basophil.
M
Eosinophils are white blood
cells and one of the immune
system components
responsible for combating
multicellular parasites and
certain infections in
vertebrates.
E
L
Lymphocytes are cellular
components of the
adaptive immune
response.

24. DiagramofHemopoiesis

25. Human bone marrow: Band neutrophil (b), neutrophilic metamyelocytes (e), late neutrophilic
myelocyte (d), normoblast (f). Wrights-Giemsa x 400.
A metamyelocyte is a cell
undergoing granulopoiesis,
derived from a myelocyte,
and leading to a band cell.
Develop into eosinophil,
basophil or neutrophil.

26. DiagramofHemopoiesis

27. Human bone marrow: Normoblasts (b, d, f) differing in sizes and degree of chromatin clumping, late
erythroblasts ( c). W-G x 400.
Normoblast (erythroblast) is a
type of red blood cell which still
retains a cell nucleus. It is the
immediate precursor of a
normal erythrocyte.
Develop into erythrocyte.
N
N N

28. DiagramofHemopoiesis

29. Human bone marrow: A megakaryocyte shedding its cytoplasm to form platelets (arrow).
W-G x 400.
Megakaryocytes belong to
myeloid progenitor.
Produced primarily by the
liver, kidney, spleen, and
bone marrow.
Develop into thrombocytes.

30. DiagramofHemopoiesis

31. Clinical Application
1. Cells, created by hemopoiesis
2. Stem cells

32. completeblood
count(CBC)
Indicators of red blood includes:
Hgb – hemoconcentration
Hgb– anemia
MCV is increased, the cell is known
as a macrocyte and when it is
decreased - microcyte.
MCV – megoblastic anemia
MCV – microcytic anemia
Color index (CI) - ratio between the
percentage of Hgb and the
percentage of red blood cells in the
blood.
It is useful in determining the type of
anemia. It is raised in pernicious
anemia and megaloblastic anemia.
It is reduced in iron deficiency
anemia.
Hgb is in erythrocytes so it is
important that the amount of Hgb
was enough, because it carries the
transfer function of O2 to the cells of
various organs.
Hgb
Erythrocytes

33. completeblood
count(CBC)
Indicators of red blood includes:
L – Leukocytosis (exist an
infection in the body, which has
launched production of white
blood cells)
L – Leukopenia
Neutrophils - leukocytic formula (wbc)
N – eosinophilia (marker of
allergies and parasitic diseases)
Leukocytes (granulocytes) - white
blood cells that are involved in the
protection (bacterial etc).
All this indicates the acute
inflammation process in the body.

34. Stem cells
Used in case when the base of the disease is a Chronic Inflammation (Chronic neuroinfections):
 Poliomyelitis;
 Cerebral Palsy;
 Blood diseases;
 Genetic disorders;
Used for reprogramming damaged (disturbed) hemopoiesis by disease.

35. Stem Cells Banks
 Public (donors) which shall be the umbilical cord /
placental blood for public use -their work is funded by the
state;
 Private storage, in which stem cells are the property of one
man and may be used only for him (he accordingly
assume all costs associated with preparation and storage).
Nowadays, there are two types of banks of stem cells from
umbilical/placental blood: