1. Macrophage
By : Anthony ( )
Retty ( )
22/09/2009

2. Macrophage Definition
A type of cell derived from white blood cells that ingests (takes in) foreign material.
is a kind of swallowing cell, which means it functions by literally swallowing up other particles or smaller cells
So what are the types of white blood cell??
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3. Types of white blood cell
picture
Diameter (μm)
Main targets
Lifetime
Neutrophil
10–12
bacteria
fungi
6 hours–few days (days in spleen and other tissue)
Eosinophil
parasites
in allergic reactions
8–12 days (circulate for 4–5 hours)
Basophil
12–15  ?
Lymphocyte
7–8
B cells: various pathogens
T cells:
Inflammatory T cell
Helper T cell
Natural killer cells: virus -infected and tumor cells.
weeks to years

4. Type of white blood cell
picture
Diameter (μm)
Main targets
Lifetime
Monocyte
14–17
Monocytes migrate from the bloodstream to other tissues and differentiate into tissue resident macrophages or dendritic cells.
hours to days
21 (human)
Phagocytosis (engulfment and digestion) of cellular debris and pathogens, and stimulation of lymphocytes and other immune cells that respond to the pathogen.
activated: days immature: months to years
Dendritic cells
Main function is as an antigen-presenting cell (APC) that activates T lymphocytes.
similar to macrophages
Macrophage

5. Macrophage Definition
Taken from Greek Words (Greek: big eaters, from makros "large" + phagein "eat"; abbr. MΦ).
Human macrophages are about 21 micrometres (  in) in diameter.
Monocytes and macrophages are phagocytes, acting in both non-specific defense (or innate immunity) as well as to help initiate specific defense mechanisms (or adaptive immunity) of vertebrate animals.
They move by action of Amoeboid movement.
Life time depends on the type of tissue, viability ranges between 6 and 16 days.
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6. Formation of Macrophage
Development in bone marrow and passes through the following steps:
stem cell  committed stem cell  monoblast  promonocyte  monocyte (bone marrow) – monocyte (peripheral blood)  macrophage (tissues)
Monocyte differention in the bone marrow proceeds rapidly (1.5 to 3 days).
During differentation, granules are formed in monocyte cytoplasma and these can be divided as in neutrophils.
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7. Formation of Macrophage
The blood monocytes are young cells (immature macrophage) that already possess migratory, chemotactic, pinocytic and phagocytic activities.
Under migration into tissues, monocytes undergo further differentiation (at least one day) to become multifunctional tissue macrophages.
Monocyte
Neutrophil
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8. Function of Macrophage
Exhibit 3 main functions in body:
1. Destroy bacteria by phagocytosis
2. Activate other immune function
3. Phagocytose apoptotic cells
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9. Function of Macrophage
1. Phagocytosis
Once it leaves blood vessel and migrated to tissue, the next job is to EAT the pathogen. This human macrophage, like neutrophil, is a professional "phagocyte" or eating cell (phago = "eating", cyte = "cell").
Furthermore, the pathogen will be digested by using enzyme from macrophage, in the end resulting antigen and waste material.
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10. Function of Macrophage
Steps of phagocytosis;
A phagosome is formed to ingest the pathogen
2. Lysosome + phagosome  phagolysosome
Pathogen is digested by using enzyme
and toxic (such as superoxide
anion or nitric oxide)
4. Secreting waste material
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11. Function of Macrophage
2. Perform Specific Immune Function
After digesting a pathogen,present antigen (identification)
Churn out powerful chemical substances (monokines) including enzymes and complement proteins.
The presentation is done by integrating it into the cell membrane, indicating to other white blood cells that the macrophage is not a pathogen, despite having antigens on its surface.
Antigen presentation results in the production of antibodies that attach to the antigens of pathogens, making them easier for macrophages to adhere to with their cell membrane and phagocytose
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12. Function of Macrophage
Secrete hormones cytokines
To attract system immune cells to the site
and activate cells involved in tissue repair
To send signaling path to injury site.
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13. Function of Macrophage
3. Phagocytose apoptotic cells
reduces the potential for an inflammatory response by ensuring that the dying cells are cleared before their intracellular contents are released.
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14. The Macrophage Work
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15. Types of Macrophage Normal macrophage Inflammatory macrophages
connective tissue (histiocytes)
liver (Kupffer's cells)
lung (alveolar macrophages)
lymph nodes (free and fixed macrophages)
spleen (free and fixed macrophages)
bone marrow (fixed macrophages)
serous fluids (pleural and peritoneal macrophages)
skin (histiocytes, Langerhans's cell) and in other tissues
Inflammatory macrophages
present in various exudates (developmental stage and not the functional state)
Derived exclusively from monocytes, thus similar properties
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16. Maintenance of Macrophage Population
3 mechanisms:
Intake of monocytes from the circulating blood,
local proliferation and
biological turnover
Under normal steady-state conditions, the renewal of tissue macrophages occurs through local proliferation of progenitor cells and not via monocyte influx.
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17. Mechanism of Inflammation
Is "dynamic response of vascularized tissues to injury“
It is a complex multi step process of tissue response to injury
Purposes:
to defend against injurious agent
Start healing & repair of injured tissue (bring defence forces such as WBC, antibodies, more nutrients and healing factors to the site of injury)
Localizes infection and prevents spread
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21. Mechanism of Inflammation
Chemical mediators : Chemical substances synthesised or released which mediate the changes in inflammation.
Histamine by mast cells - vasodilatation.
Prostaglandins – Cause pain & fever.
Bradykinin - Causes pain.
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22. Mechanism of Inflammation
Clinical signs of inflammation (due to vascular permeability which allows for phagocytic chemotaxis)
Lewis triple response
Flush (redline) : capillary dilatation
Flare (red zone) : arteriolar dilatation
Weal (edema) : exudation
Classic five signs
Rubor(redness)
Tumor(swelling)
Calor(Heat)
Dolor (pain)
Loss of function
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23. The 5 Cardinal Signs of
Heat Redness Swelling Pain Loss Of Function

24. Thank You
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