1. Hematopoiesis (The formation of Blood Cells)‏

2. Where Does it Happen? Occurs in the Red Bone Marrow
Red Bone Marrow is Found in the flat bones of the:
1. Pelvis
2. Ribs
3. Sternum
4. Ends of the Femur and Humerus in adults.

3. How is it controlled?
Each blood cell type is produced according to need
Levels of the hormone Erythropoietin (EPO) control the rate of RBC production
EPO is produced by the kidneys

4. How does EPO work?
We always have a little EPO flowing through us to ensure constant RBC production
If Oxygen levels fall, levels of EPO rise and more RBC’s are produced
The increase in EPO stimulates the red bone marrow to produce the new cells
High levels of oxygen in the blood will lower the amount of EPO and slow down RBC production

5. The Hematocytoblast
Common stem cell that gives rise to all the formed elements of blood
Located in the red bone marrow
Forms two types of cells
1. Lymphoid Stem cell- produces all lymphocytes
2. Myeloid Stem Cell- produces all other formed elements (RBC’s plasma)

7. Formation and Destruction of Red Blood Cells
Process Diagrams Step-by-Step
Copyright © 2007 by John Wiley & Sons, Inc.

8. 1 Key: Red blood cell death and phagocytosis Macrophage in
spleen, liver, or
red bone marrow
Key:
in blood
in bile

9. 2 1 Key: Globin Heme Red blood cell death and phagocytosis
Macrophage in
spleen, liver, or
red bone marrow
Key:
in blood
in bile

10. 3 2 1 Key: Amino Reused for protein synthesis acids Globin Heme
Red blood cell
death and
phagocytosis
Macrophage in
spleen, liver, or
red bone marrow
Key:
in blood
in bile

11. 3 4 2 1 Key: Amino Reused for protein synthesis acids Globin Fe3+ Heme
Transferrin 1
Red blood cell
death and
phagocytosis
Macrophage in
spleen, liver, or
red bone marrow
Key:
in blood
in bile

12. 3 4 5 2 1 Key: Amino Reused for protein synthesis acids Globin Fe3+
Heme
Ferritin
Transferrin
Liver 1
Red blood cell
death and
phagocytosis
Macrophage in
spleen, liver, or
red bone marrow
Key:
in blood
in bile

13. 3 6 4 5 2 1 Key: Amino Reused for protein synthesis acids Fe3+
Transferrin
Globin 6 4 5
Fe3+ 2
Heme
Ferritin
Transferrin
Liver 1
Red blood cell
death and
phagocytosis
Macrophage in
spleen, liver, or
red bone marrow
Key:
in blood
in bile

14. 7 3 6 4 5 2 1 Key: Amino acids Reused for protein synthesis Fe3+
Transferrin
Globin 6 4 5
Fe3+ 2
Heme
Ferritin
Fe3+
Transferrin +
Globin +
Liver
Vitamin B12 1
Red blood cell
death and
phagocytosis +
Erythopoietin
Macrophage in
spleen, liver, or
red bone marrow
Key:
in blood
in bile

15. 7 3 6 4 5 2 1 8 Key: Circulation for about 120 days Amino acids
Reused for
protein synthesis
Fe3+
Transferrin
Globin 6 4 5
Fe3+ 2
Heme
Ferritin
Fe3+
Transferrin +
Globin +
Liver
Vitamin B12 1
Red blood cell
death and
phagocytosis +
Erythopoietin 8
Erythropoiesis in
red bone marrow
Macrophage in
spleen, liver, or
red bone marrow
Key:
in blood
in bile

16. 7 3 6 4 5 2 9 1 8 Key: Circulation for about 120 days Amino acids
Reused for
protein synthesis
Fe3+
Transferrin
Globin 6 4 5
Fe3+ 2
Heme
Ferritin
Fe3+
Transferrin +
Globin 9 +
Biliverdin
Bilirubin
Liver
Vitamin B12 1
Red blood cell
death and
phagocytosis +
Erythopoietin 8
Erythropoiesis in
red bone marrow
Macrophage in
spleen, liver, or
red bone marrow
Key:
in blood
in bile

17. 7 3 6 4 5 2 9 1 10 8 Key: Circulation for about 120 days Amino acids
Reused for
protein synthesis
Fe3+
Transferrin
Globin 6 4 5
Fe3+ 2
Heme
Ferritin
Fe3+
Transferrin +
Bilirubin
Globin 9 +
Biliverdin
Bilirubin
Liver
Vitamin B12 1
Red blood cell
death and
phagocytosis + 10
Erythopoietin 8
Erythropoiesis in
red bone marrow
Macrophage in
spleen, liver, or
red bone marrow
Key:
in blood
in bile

18. 7 3 6 4 5 2 9 11 1 10 8 12 Key: Circulation for about 120 days Amino
acids
Reused for
protein synthesis
Fe3+
Transferrin
Globin 6 4 5
Fe3+ 2
Heme
Ferritin
Fe3+
Transferrin +
Bilirubin
Globin 9 +
Biliverdin
Bilirubin
Liver
Vitamin B12 1
Red blood cell
death and
phagocytosis 11 + 10
Erythopoietin
Small
intestine 8
Erythropoiesis in
red bone marrow
Bilirubin 12
Macrophage in
spleen, liver, or
red bone marrow
Urobilinogen
Bacteria
Key:
in blood
Stercobilin
in bile
Feces

19. 7 3 6 4 5 2 9 11 1 10 8 13 12 Key: Circulation for about 120 days
Amino
acids
Reused for
protein synthesis
Fe3+
Transferrin
Globin 6 4 5
Fe3+ 2
Heme
Ferritin
Fe3+
Transferrin +
Bilirubin
Globin 9 +
Biliverdin
Bilirubin
Liver
Vitamin B12 1
Red blood cell
death and
phagocytosis 11 + 10
Erythopoietin
Small
intestine
Kidney 8
Erythropoiesis in
red bone marrow
Bilirubin 13 12
Urobilin
Macrophage in
spleen, liver, or
red bone marrow
Urobilinogen
Bacteria
Key:
in blood
Stercobilin
in bile
Urine
Feces

20. 7 3 6 4 5 2 9 11 1 10 8 13 12 Key: 14 Circulation for about 120 days
Amino
acids
Reused for
protein synthesis
Fe3+
Transferrin
Globin 6 4 5
Fe3+ 2
Heme
Ferritin
Fe3+
Transferrin +
Bilirubin
Globin 9 +
Biliverdin
Bilirubin
Liver
Vitamin B12 1
Red blood cell
death and
phagocytosis 11 + 10
Erythopoietin
Small
intestine
Kidney 8
Erythropoiesis in
red bone marrow
Bilirubin 13 12
Urobilin
Macrophage in
spleen, liver, or
red bone marrow
Urobilinogen
Bacteria
Key:
in blood
Stercobilin
Large
intestine 14
in bile
Urine
Feces