1. White Blood Cells Prepared by Dr. Hamad ALAssaf Alassaf_h@yahoo.com
2015

3. Leukocytes / White Blood Cells
Granulocytes (65%)
- neutrophils, eosinophils, basophils
- formed in bone marrow
Monocytes (5%)
- tissue macrophages
Lymphocytes (30%)
- formed in lymph tissue
- life span: hours to years

4. Leukocytes Classification
Granulocytes Non- Granulocytes
Neutrophils - Monocytes
Eosinophils - Lymphocytes
Basophils
Polymorphonuclear Mononuclear
Phagocytes Non-phagocytes
Neutrophils, monocytes - Lymphocytes
Macrophages, eosinophils - Basophils
Granulocytes granules in cells
Polymorphnuclear Multilobed nucleus
Phagocytes

5. Phagocytic Cells 2- Monocytes/Macrophages
1- Polymorphonuclear Neutrophils
- non-dividing, short-lived (6 hours to a few days)
- dominant number in bloodstream
2- Monocytes/Macrophages
- long-lived cells (months)
- do not circulate
- present in tissue, particularly in lungs, spleen, liver, lymph nodes
- tissue macrophage system
Neutrophils 9-10 days
5-7 days in maturation and storage, 2-3 days in bone marrow

6. Actions of Phagocytic Cells
1. Margination
2. Diapedesis
3. Ameboid Motion
4. Chemotaxis
5. Phagocytosis

7. Actions of Phagocytic Cells

8. Phagocytosis 2. Engulfment 1. Binding 3. Phagosome formation
Acidification
proteolysis
MHC II
4. Lysosome fusion
6-Antigen
presentation
5 Membrane disruption

9. Cell-mediated Response to Inflammation
1. Tissue macrophages:
- already present in tissue
2. Neutrophil invasion:
- margination, diapedesis, chemotaxis
- stimulation of bone marrow to release stored leukocytes, 4-5 hours
3. Macrophage proliferation:
- invasion by circulating monocytes (several hours to increase size)
4. Stimulation of granulocyte and monocyte production:
- growth factors produced by tissue macrophages (TNF, IL-1, Cell stimulating factor)

10. NORMAL PRODUCTION
INFECTION
Marrow
pool
Increased
Production
Production
Decreased
marrow pool
Bone
Bone
Increased circulation
Increased margination
Circulating and marginated pools
Blood vessel
Blood vessel
Increased
Transmigration
Transmigration
Tissue
Tissue
Site of inflammation

11. Granulocytes ~ 0.5% of total white blood cells EOSINOPHILS: BASOPHILS:
- active against parasites, skin diseases, chronic infections
- phagocytic and immunomodulatory, decrease inflammation
- life span 5 days
BASOPHILS:
~ 0.5% of total white blood cells
- basophils similar to mast cells
- release primarily histamine, some bradykinin
- release due to binding of IgE
- Life span a few hours to a few days

12. Important terms
Leukopenia : decrease in the number of white blood cells. example: bone marrow suppression
Leukocytosis : increase in the number of white blood cells. example : bacterial infections
Leukemia : (cancerous) uncontrolled production of white blood cells

13. Neutropenia Neutropenia: decreased number of neutrophils due to:
Decreased production
Increased neutrophil destruction (chronic infections)
Agranulocytosis: severe neutropenia due to:
production failure
due to irradiation
exposure to chemicals
drugs
Decrease production
inherited stem cell disorders
chemical toxicity
Increased destruction
infections,
immune mechanisms

14. Immunity It is a special defense mechanism which is mobilized
when the body is invaded by a foreign organism.

15. Immunity Innate = (present since birth)
- ability to resist damaging organisms and toxins
- skin, gastric acids, tissue neutrophils and macrophages,
complement
Acquired = (developed by exposure to specific invading
agents).
- humoral ----> circulating antibodies
- cellular ----> activated cells

17. Sequence - Dormant lymphocytes - Invasion of body by foreign antigen
- Phagocytosis by macrophages
- Presentation of antigen to lymphocytes
2 x1012 lymphocytes

18. Antigen
An antigen: is a substance that can induce an immune response when introduced into an immunocompetent host and that can react with the antibody produced from that response.
Macromolecule
Protein
polysaccharide
Most antigens have variety of antigenic determinants

19. Lymphocytes T- and B-Cells
T8-supressor
Pre-T
Cell
T-Cell
Thymus
T4-helper
Bone Marrow
Stem cell
Pre-B
Cell
B-Cell
Plasma Cell
Liver and Bone marrow
IgG
IgA
IgM
IgD
IgE

20. T-cells Cytotoxic Cells Helper Cells ( CD-4 cells) Suppressor Cells
kill infected cells
Helper Cells ( CD-4 cells)
activate macrophages and B-cells
Suppressor Cells
regulate activity