this presentation contain : the hematopoiesis in adult, and how regulated in all stages of blood cells production

1. Developed by Dr.
Abdulrazzak Othman Alagbare
Clinical Pathologist -Hematology Lecturer _ MD
Blood cells production
Hematopoiesis –in adult

2. Hematopoiesis –in adult
Introduction
Hematopoiesis is a term describing the formation and
development of blood cells.
 Cells of the blood are constantly being lost or
destroyed.
 Thus, to maintain homeostasis, the system must have
the capacity for self renewal.
This system involves:
a) Proliferation of progeny stem cells
b) Differentiation and maturation of the stem cells into
the functional cellular elements.

3. 
Types of hematopoiesis
 Intramedullary hematopoiesis. It is normal and
occur only in the bone marrow
 Extramedullary hematopoiesis. describes
hematopoiesis outside the bone marrow
environment, primarily the liver and spleen. (it is
abnormal)
===========================
 Extramedullary hematopoiesis may occur in fetal
hematopoietic tissue (liver and spleen) of an adult when
the bone marrow cannot meet the physiologic needs of
the tissues
Types of hematopoiesis

4. introduction
 Blood cells production called hematopoiesis.
1-The main organs for hematopoies in all human life
are
1. Liver and Spleen (prenatal period)
2. And the bone marrow(BM) (adult period)
2-The secondary hematopoietic organ called the
reticuloendothelia system (RES)
 The first cell which produce all the other cells
called Pluripotent stem cells (PSC) or
hemocytoblasts
Blood cells production

5. The stem cells
 Definition: They are cells which give new generation of
cells, and existing in the bone marrow exclusively and
they are:
 The sources of the hematopoietic stem ells are the
mesenchymal ells of the yolk sac and they are
1-Pluripotent stem cells (PSC) or hemohistoblast
2-Myeloid stem cell (MSC)
3-Lymphoid stem cell (LSC)
MSC and LSC also called
 Progenitor cells,
 Committed cells
 or hematopoietic cells

6. Pluripotent stem cells (PSC) or
(hemohistoblast)
Properties
Pluripotent stem cells has the
following properties
1- Self-renewal  Has the ability to
renew its selves
2-Multipotentiality  Can produce
another cells (pluripotent cells )
3-Mothers of all blood cells
4-Existing mainly in the bone marrow

8. Progenitor cells
What are progenitor cells?
They also called: hematopoietic or
committed cells
They are the first cells which produce
from the stem cell
They are two
1-Myeloid stem cell (MSC)
2- Lymphoid stem cell (LSC)

9. Progenitor cells
The myeloid stem cell
1.Exist in the bone marrow
2.Produce the cells called Myeloid group
or myeloid sera
The lymphoid stem cell
1.Exist in the bone marrow
2.Produce the cell called Lymphoid group
or Lymphoid sera

10. The myeloid stem cell
The cells which produced from the MSC and
existing in the peripheral blood are
CFU-myeloid stem cell
A. CFU-E
I. Eryhtrocytes
B. CFU-GM
I. Granulocytes
II. Monocytes
C. CFU-M
I. Megakaryocytes (Platelets)

11. Progenitor cells culture
In culture media the progenitor cells are
defined as colony forming unit (CFU).
Each of the CFUs in turn can produce a
colony of one hematopoietic lineage
under appropriate growth conditions

12. Early progenitor cells of myeloid
group
7/1/2023
1
2
CFU-E (erythrocytes)
CFU-Meg (megakaryocyte)
CFU-Eo –Bas (Eosinophil and Basophil)
CFU-GM (Granular and monocytes

13. The lymphoid stem cell
The cells which produced from the LSC
and existing in the peripheral blood are
I. T Lymphocytes
II. B Lymphocytes

14. Regulation of hematopoiesis
For blood cells production needs  regulation and control to
produce  adequate cells and no more than the normal needs, for
that there are many factors do that. There should be a balance
between cell production and cell death except at the times of
requirement
They called
 Hemopoietic growth factors
 Colonies stimulated factors (CSF)
 or cytokines
Controlled cell death
Controlled cell production

15. Haemopoietic growth
factors
1. Chemical nature: glycoprotein hormones
2. Source: from all the body cells (T –
lymphocytes, monocytes, kidney, liver,
hematopoietic cells)
3. Action: stimulate, regulate and maintain
the blood cells Proliferation,
Differentiation , Maturation and function

16. Haemopoietic growth
factors
These factors have the capacity to stimulate the
proliferation of their target progenitor cells when used
as a sole source of stimulation The most important are
 GM-CSF
 Granulocyte-Macrophage colony stimulating
factor
 M-CSF
 Macrophage colony stimulating factor
 Erythropoietin (EPO)
 Erythropoiesis stimulating hormone
 Thrombopoietin (TPO)
 Stimulates megakaryopoiesis

17.  Cytokines  especially for stem cells and lymphocytes
 IL 1 (Interleukin 1)
 IL 3
 IL 4
 IL 5
 IL 6
 IL 9
 IL 11
 TGF-β
 SCF (Stem cell factor, also known as kit-ligand)
===========
Cytokines have no (e.g IL-1) or little (SCF) capacity to
stimulate cell proliferation on their own, but are able
to synergise with other cytokines to recruit nine cells
into proliferation
Haemopoietic growth factors
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18. Other regulator of blood cells production (
hormones)
a)Androgen
b)Corticosteroid
c)Prostaglanding E2
d)Thyroxin

19. Stem cells and blast cells
Stem cells or Progenitor Cells
1. Source of differentiated cells
2. Originated in the bone marrow
3. Capable to give new cells
4. Regulated by the cytokines or growth factors
Example
• CFU-E (erythrocytes)
• CFU-Meg (megakaryocyte)
• CFU-Eo –Bas (Eosinophil and Basophil)
• CFU-GM (Granular and monocytes

20. Stem cells and blast cells
Blast cells or Precursor Cells
1. Are cells originated in the bone marrow
2. Not capable to give new cells
3. Developing to be mature and function cells
Example :
• Proerythroblast
• Lymphblast,
• Myelocytoblast
• Megakaryoblast

21. Blood Cell Production (Hemopoiesis)
 Hemopoietic tissues produce blood cells
 The Red bone marrow is the active part of bones
which produce blood cells especially in the first 2
years of the life
 Red bone marrow produces RBCs, WBCs and
platelets
 Stem cells called hemocytoblasts, multiply
continually and are pluripotent (capable of
differentiating into multiple cell lines)
 committed cells are destined to continue down one
specific cell line
Summary

22. END OF THE LESSON