Define hematopoiesis. Understand hematopoiesis. Explain conditions related to hematopoiesis. Determine hematopoiesis disorders. Explain the regulation of hematopoiesis.

1. HEMATOPOIESIS
BY: Temwa Nyirenda & Edgar
Zgambo

2. OBJECTIVES
• Define hematopoiesis.
• Understand hematopoiesis.
• Explain conditions related to hematopoiesis.
• Determine hematopoiesis disorders.
• Explain the regulation of hematopoiesis.

3. Defining &Understanding Hematopoiesis
• Hema: blood
• Poiesis: formation
1.Note:
• About 1 percent of the body's blood cells must be
replaced every day.( so we can take it as the role)
• White blood cells have the shortest life span,
sometimes surviving just a few hours to a few
days, while red blood cells can last up to 120
days or so.

4. Defining &Understanding Hematopoiesis
• Hematopoiesis(hemopoiesis) is the process of
blood cell formation and development in the
bone marrow.
• The process start with the hematopoietic stem
cell(plurepotent stem cell).
• Pluripotent meaning it has the ability to
differentiate into different types of the stem
cells.

5. Hematopoiesis Process
• The process begins with unspecialized stem cells
multiplication, where some of the cells are
transformed into precursors cells destined to
become a particular type of blood cell .

6. HEMATOPOIETIC
• HEMATOPOIESIS

7. Stages of hematopoiesis
• Differentiation of the stem cells into myeloid
stem cell and lymphoid stem cell.
• Series of progenitor cells formation e.g. Colony
Forming Unit(CFU)-Erythrocytes, CFU-Meg,
CFU-Glanularcytes & macrophages(GM)
• Formation of precursor cells from the progenitor
cells.
• Maturation process
• Formation of formed element of blood e.g. red
blood cells, white blood cells and platelets.

10. Where does it occur mainly???
• Mainly it occurs in the bone marrow of the
medulla cavity.

11. Cont.….
• It also occurs within the hematopoietic system,
which includes organs and tissues such as the
bone marrow, liver, and spleen.
• This occurs in many conditions depending on
the body needs.

12. • This occurs in many conditions depending on
the body needs.
So what are the
conditions ????

13. • Embryonic hematopoiesis : refers to
hematopoiesis that occur in the yolk sac of an
embryo
• blood formation occurs in aggregates of blood
cells in the yolk sac called blood islands. As
development progresses, blood formation occurs
in the spleen, liver, and lymph nodes. When
bone marrow develops,.

14. Embryonic hematopoiesis
• Extra medullary hematopoiesis (EH):
refers to the hematopoiesis that occurs in organs
other than bone marrow.

15. Extra medullary hematopoiesis

16. Disorders of Hematopoiesis
• Peripheral pancytopenia: This is a condition that
occurs when a person has low counts for all
three types of blood cells: red blood cells, white
blood cells, and platelets.
 Pancytopenia is usually due to a problem
with the bone marrow that produces the blood
cells.
• Bicytopenia: A deficiency in two of the three
cell lines in the blood, namely erythrocytes,
leukocytes and platelets.

17. • Disorders
So what are the
regulation ???

18. Regulation of Hematopoiesis
• Regulation occurs via cell-cell interactions and by
way of the generation of specific hormones and
cytokines e.g.
Erythropoietin.
interleukin 3, granulocyte-monocyte colony-stimulating factor
(GM-CSF).
monocyte-macrophage colony-stimulating factor (M-CSF),
 granulocyte colony-stimulating factor (G-CSF), interleukin 5,
interleukin 4.
 less well-defined factors, including the megakaryocyte growth
factors.

19. •End of the presentation….
unless there are questions ….

20. •
•Thank you for listening !!!!!!

21. References
• https://medical-
dictionary.thefreedictionary.com/hematopoiesis
• https://study.com/academy/lesson/red-blood-
cell-destruction-causes-treatment-options.html