Hematopoiesis (The formation of Blood Cells). Where Does it Happen? Occurs in the Red Bone Marrow...

Hematopoiesis (The formation of Blood Cells)

Where Does it Happen?

• Occurs in the Red Bone Marrow• Red Bone Marrow is Found in the flat

bones of the:1. Pelvis2. Ribs3. Sternum4. Ends of the Femur and Humerus in adults.

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

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

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 cells1. Lymphoid Stem cell- produces all lymphocytes2. Myeloid Stem Cell- produces all other formed elements (RBC’s plasma)

Formation and Destruction of Red Blood Cells

Process Diagrams Step-by-Step

Copyright © 2007 by John Wiley & Sons, Inc.

Red blood celldeath andphagocytosis

Key:in blood

in bile

Macrophage inspleen, liver, orred bone marrow

1

Globin


Key:in blood

in bile


Heme2

1

Aminoacids

Reused forprotein synthesisGlobin


Key:in blood

in bile


Heme

3

2

1

Aminoacids



Transferrin

Fe3+

Key:in blood

in bile


Heme

4

3

2

1

Aminoacids



Transferrin

Fe3+

Liver

Key:in blood

in bile


FerritinHeme

54

3

2

1

Aminoacids



Transferrin

Fe3+

Fe3+ Transferrin

Liver

Key:in blood

in bile


FerritinHeme

654

3

2

1

Aminoacids



Transferrin

Fe3+

Fe3+ Transferrin

Liver

+Globin

+Vitamin B12

+Erythopoietin

Key:in blood

in bile


FerritinHeme Fe3+

7

654

3

2

1

Aminoacids


Circulation for about120 days


Transferrin

Fe3+

Fe3+ Transferrin

Liver

+Globin

+Vitamin B12

+Erythopoietin

Key:in blood

in bile

Erythropoiesis inred bone marrow


FerritinHeme Fe3+

8

7

654

3

2

1

Aminoacids




Transferrin

Fe3+

Fe3+ Transferrin

Liver

+Globin

+Vitamin B12

+Erythopoietin

Key:in blood

in bile



FerritinHeme

Biliverdin Bilirubin

Fe3+

9

8

7

654

3

2

1

Aminoacids



Bilirubin


Transferrin

Fe3+

Fe3+ Transferrin

Liver

+Globin

+Vitamin B12

+Erythopoietin

Key:in blood

in bile



FerritinHeme


Fe3+

10

9

8

7

654

3

2

1

Aminoacids


Stercobilin

Bilirubin

Urobilinogen

Feces

Smallintestine


Bacteria

Bilirubin


Transferrin

Fe3+

Fe3+ Transferrin

Liver

+Globin

+Vitamin B12

+Erythopoietin

Key:in blood

in bile



FerritinHeme


Fe3+

12

111

0

9

8

7

654

3

2

1

Aminoacids


Urine

Stercobilin

Bilirubin

Urobilinogen

Feces

Smallintestine


Bacteria

Bilirubin


Transferrin

Fe3+

Fe3+ Transferrin

Liver

+Globin

+Vitamin B12

+Erythopoietin

Key:in blood

in bile


Kidney


Ferritin

Urobilin

Heme


Fe3+

13

12

111

0

9

8

7

654

3

2

1

Aminoacids


Urine

Stercobilin

Bilirubin

Urobilinogen

Feces

Largeintestine

Smallintestine


Bacteria

Bilirubin


Transferrin

Fe3+

Fe3+ Transferrin

Liver

+Globin

+Vitamin B12

+Erythopoietin

Key:in blood

in bile


Kidney


Ferritin

Urobilin

Heme


Fe3+

14

13

12

111

0

9

8

7

654

3

2

1

Hematopoiesis (The formation of Blood Cells). Where Does it Happen? Occurs in the Red Bone Marrow...

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Transcript of Hematopoiesis (The formation of Blood Cells). Where Does it Happen? Occurs in the Red Bone Marrow...