4. MONOCYTES

* Exit blood (diapedesis) to become macrophages

* 2-6 % of the WBC's

* Phagocytic = defend against viruses and bacteria

Life span of WBCLife span of WBC

The life of granulocytes is normally 4 The life of granulocytes is normally 4 to 8 hours in the blood and another 4 to 8 hours in the blood and another 4 – 5 days in tissue where they needed– 5 days in tissue where they needed

The monocytes 10 – 20 hours in the The monocytes 10 – 20 hours in the blood and in the tissues they become blood and in the tissues they become larger size and become tissue larger size and become tissue macrophagemacrophage

Lymphocytes have life span weeks or Lymphocytes have life span weeks or months depends on the needsmonths depends on the needs

Leukocyte Leukocyte

Leukocyte (WBC) are the mobile units of the Leukocyte (WBC) are the mobile units of the body protective systembody protective system

They are formed in the bone marrow They are formed in the bone marrow (granulocytes and monocytes and few (granulocytes and monocytes and few lymphocytes) and in the lymph tissue lymphocytes) and in the lymph tissue (lymphocytes)(lymphocytes)

Leukocytes work in two ways to prevent Leukocytes work in two ways to prevent diseasedisease

1.1. Destroying invading bacteria/viruses by Destroying invading bacteria/viruses by phagocytosisphagocytosis

2.2. By forming antibodies By forming antibodies

Five types of WBCFive types of WBC Three types of the cells are Three types of the cells are

polymorphonuclear cells. All have polymorphonuclear cells. All have granular appearancegranular appearance

The granulocyte and monocytes The granulocyte and monocytes protect the body against invading protect the body against invading organism by phagocytosisorganism by phagocytosis

Leukocyte Leukocyte

Human being has about 7000 Human being has about 7000 WBC /micro liter WBC /micro liter

Normal percentage areNormal percentage are

NeutrophilsNeutrophils 62%62%

EosinphilsEosinphils 2.3%2.3%

BasophilsBasophils 0.4%0.4%

MonocytesMonocytes 5.3%5.3%

LymphocytesLymphocytes 30%30%

Leukocyte Leukocyte

Neutrophils and Monocytes Neutrophils and Monocytes (macrophages) attack the invading (macrophages) attack the invading bacteria, viruses bacteria, viruses

WBC can squeeze through the blood WBC can squeeze through the blood capillaries by capillaries by diapedesisdiapedesis

WBC can move by ameboid motionWBC can move by ameboid motion WBC are attracted to inflamed tissue WBC are attracted to inflamed tissue

area by Chemotaxis area by Chemotaxis

Leukocyte Leukocyte

Phagocytosis which means cellular ingestion Phagocytosis which means cellular ingestion of the offending agentof the offending agent

Macrophages are much more powerful Macrophages are much more powerful phagocytes than neutrophilsphagocytes than neutrophils

Lysosome in the neutrophil and macrophage Lysosome in the neutrophil and macrophage come in contact with the phagocytic vesicle come in contact with the phagocytic vesicle and digestion of phagocytized particles beginand digestion of phagocytized particles begin

Both neutrophils and macrophages contain Both neutrophils and macrophages contain proteolytic enzyme. The lysosome in the proteolytic enzyme. The lysosome in the macrophages contain lipases macrophages contain lipases

Leukocyte Leukocyte

Neutrophils and Neutrophils and macrophages kill macrophages kill

bacteriabacteria Neutrophils and macrophages Neutrophils and macrophages

contains contains oxidizing agentoxidizing agent such as such as HH22OO22 which is lethal to most which is lethal to most bacteriabacteria

Monocyte-Macrophage Monocyte-Macrophage Cell SystemCell System

The combination of monocytes, The combination of monocytes, mobile macrophages, fixed tissue mobile macrophages, fixed tissue macrophages and specialized macrophages and specialized endothelial cells in the bone marrow, endothelial cells in the bone marrow, spleen and lymph nodes is called spleen and lymph nodes is called Monocyte-Macrophage cell system Monocyte-Macrophage cell system or or reticuloendothelialreticuloendothelial system system

Tissue macrophage in Tissue macrophage in the skinthe skin

Once the skin broken, infection Once the skin broken, infection occur and inflammation ensuesoccur and inflammation ensues

Macrophages in subcutaneous Macrophages in subcutaneous tissue (Histiocyte) destroy the tissue (Histiocyte) destroy the infectious agent by performing infectious agent by performing phagocytosis phagocytosis

Macrophages in the Macrophages in the lymph nodeslymph nodes

Large numbers of macrophages line Large numbers of macrophages line the lymph sinuses and if any the lymph sinuses and if any particles enter the sinuses the particles enter the sinuses the macrophages phagocytize themmacrophages phagocytize them

Alveolar macrophages in Alveolar macrophages in the lungsthe lungs

Invading organisms enter the body Invading organisms enter the body through the lungsthrough the lungs

Tissue macrophages are present as Tissue macrophages are present as integral components of alveolar integral components of alveolar wallswalls

They can phagocytize particles that They can phagocytize particles that entrapped in the alveoli entrapped in the alveoli

Macrophages Kupffer cells in Macrophages Kupffer cells in the liver sinusoidsthe liver sinusoids

Bacteria invading the body from Bacteria invading the body from ingested food through gastrointestinal ingested food through gastrointestinal tract into the portal bloodtract into the portal blood

Blood passes through sinusoids of the Blood passes through sinusoids of the liver which lined with tissue liver which lined with tissue macrophages called Kupffer cellsmacrophages called Kupffer cells

These cells form such an effective These cells form such an effective particulate filtration to prevent passing particulate filtration to prevent passing bacteria from the gastrointestinal tract bacteria from the gastrointestinal tract to the blood circulation system to the blood circulation system

Macrophages of the Macrophages of the spleen and bone marrowspleen and bone marrow

Macrophages of the spleen and bone Macrophages of the spleen and bone marrow is another defense against marrow is another defense against organism that succeeded to enter organism that succeeded to enter the blood circulation the blood circulation

Inflammation is the body response to Inflammation is the body response to infection or injury. The functions of infection or injury. The functions of inflammation are to destroy or inflammation are to destroy or inactivate foreign invaders and to inactivate foreign invaders and to set stage for tissue repair set stage for tissue repair

InflammationInflammation

Inflammation Inflammation

1.1. Vasodilation of the blood vessels with Vasodilation of the blood vessels with consequent excess blood flowconsequent excess blood flow

2.2. Increased permeability of the capillaries Increased permeability of the capillaries allowing leakage of large quantity of fluid allowing leakage of large quantity of fluid

3.3. Often clotting of the fluidOften clotting of the fluid

4.4. Migration of large numbers of granulocytes and Migration of large numbers of granulocytes and monocytes into the tissuemonocytes into the tissue

5.5. Swelling of the tissue cellsSwelling of the tissue cells Some products that cause these reaction are Some products that cause these reaction are

histamine, serotonin and prostaglandinshistamine, serotonin and prostaglandins

The first result of inflammation is to “wall-off” The first result of inflammation is to “wall-off” the area of injury from the remaining tissue. the area of injury from the remaining tissue.

The intensity of the inflammatory process is The intensity of the inflammatory process is proportional to the degreeproportional to the degree

Staphylococci release lethal toxins Staphylococci release lethal toxins InflammationInflammation

Rapid Wall OffRapid Wall Off

Streptococci no tissue destruction Streptococci no tissue destruction Inflammation Inflammation

Slow Wall OffSlow Wall Off

Effect of inflammation Effect of inflammation “walling-off”“walling-off”

Within few minutes after Within few minutes after inflammation begins, tissue inflammation begins, tissue macrophages begins their macrophages begins their phagocytic action.phagocytic action.

Many fixed tissue macrophages Many fixed tissue macrophages break loose from their attachment break loose from their attachment forming the first line of defense forming the first line of defense against infectionagainst infection

Macrophage and Macrophage and Neutrophil Responses Neutrophil Responses During InflammationDuring Inflammation

Neutrophil invasion of the inflamed area is the Neutrophil invasion of the inflamed area is the second line of defensesecond line of defense

Neutrophils begins to invade the inflamed area Neutrophils begins to invade the inflamed area from the bloodfrom the blood

This is caused by products from the inflamed area This is caused by products from the inflamed area which initiate the following reactions:which initiate the following reactions:

1.1. Alter the inside surface of the capillary causing Alter the inside surface of the capillary causing neutrophils stick on the capillary walls. This called neutrophils stick on the capillary walls. This called marginationmargination

2.2. Caused intracellular attachment to loosen Caused intracellular attachment to loosen diapedesisdiapedesis

3.3. Other product caused Other product caused chemotaxischemotaxis

Macrophage and Macrophage and Neutrophil Responses Neutrophil Responses During InflammationDuring Inflammation

Second macrophages invasion is a Second macrophages invasion is a third line of defensethird line of defense

Monocyte from the blood enter the Monocyte from the blood enter the inflamed tissues and enlarged to inflamed tissues and enlarged to become macrophagesbecome macrophages

Macrophages can phagocytize more Macrophages can phagocytize more bacteria larger particles than bacteria larger particles than neutrophils neutrophils

Macrophage and Macrophage and Neutrophil Responses Neutrophil Responses During InflammationDuring Inflammation

Increased production of Increased production of granulocytes and monocytes by bone granulocytes and monocytes by bone marrow is the fourth line of defensemarrow is the fourth line of defense

Macrophage and Macrophage and Neutrophil Responses Neutrophil Responses During InflammationDuring Inflammation