Defense Mechanism: White Blood Cells
One of the functions of your blood is for bodily defenses from infections held responsible by your white blood cells. White Blood cells are also known as Leukocytes, like RBC is know as Erythrocytes. WBCs undergo a differentiation process called Leukopoiesis.Furthermore, your WBC is branched into 5 more different types of cells that have more specific roles in the blood.
Your WBC are formed in your bone marrow (monocyte, neutrophil, eosinophil and basophil) and your lymphoid tissues (lymphocyte) such as your lymph nodes and spleen. Your WBC's lifespan depends on the type of cell, and is shortened due to infections in the body. Two features of WBC are agranulated, no granules, and granulated, having granules, and all of them contains nucleus (nucleated).
Your WBC are formed in your bone marrow (monocyte, neutrophil, eosinophil and basophil) and your lymphoid tissues (lymphocyte) such as your lymph nodes and spleen. Your WBC's lifespan depends on the type of cell, and is shortened due to infections in the body. Two features of WBC are agranulated, no granules, and granulated, having granules, and all of them contains nucleus (nucleated).
AGRANULOCYTES
The Scavenger
Monocytes are the first line of defense against bacterial infection in our body. They become Macrophages of the skin and other parts of the body and become phagocytic. Monocytes are agranulated, unilobed, nucleated cell that is kidney-shaped and is formed in the bone marrow along other granulated leukocytes except lymphocytes.
Monocytes are about 4-6% in the WBC differential account. They are immobilized together with neutrophils in defense mechanism. they have a short transit time in the blood wandering and through capillary membranes and to tissues. Once they swell, they become tissue macrophage, and can live for months or years, unless they are destroyed by performing phagocytic functions.
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The Guard Dog
Life span of a lymphocyte varies from 100-300 days or even years, depending on the body's need. There are types of lymphocytes namely the T cell, B cell and killer cells. The T cell orchestrates the immune system's response to infected or malignant cells. B cells recognize free antigen molecules into plasma cells that secrete immunoglobulin (antibodies) that inactivate antigens. Meanwhile, killer cells are T cells with CD8 receptors (glycoprotein receptor for T cells) that recognizes antigens on the surface of a virus-infected cell and binds to the infected cell and kills it.
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Lymphocytes are the only leukocytes originating from lymphoid tissues. they are characterized by darkly-stained large nucleus with denser cytoplasm. They are agranulated, unilobed nucleated leukocyte that function as immune response
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GRANULOCYTE
Neutrophil
Neutrophils are leukocytes originating from the bone marrow. They are granulocytes that are multilobed (mostly up to 5 if they are very old) nucleated leukocyte. Their lobes are attached by a chromatin fiber and are lightly stained by neutral, acidic, or basic dyes, since their name originates from the word neutral.
They are the most numerous leukocyte accounting to 50-70% of the total number of WBC differential count. Along with monocytes, they are the second line of defense against bacterial infection
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Eosinophil
Eosinophil are also called acidophil because it is only dyed in eosin dyes that are acidic in nature. They account 1-3% in WBC differential count. they are multilobed nucleated granulocytes (up to 3) similar to the neutrophil's lobed nucleus. They appear brick red under eosin dyes.
Eosinophils are responsible for detoxification, disintegration and removal of proteins. They increase in number during parasitic infections and allergies, together with basophils. Eosinophils contain histamine, and proteins like eosinophil peroxidase, ribonuclease, deoxyribonuclease, lipase, plasminogen and other major basic proteins.
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Basophil
Basophils, from the word base, are stained with basic dyes and appear dark blue. They are the most rarest seen leukocyte in the WBC differential count, about 0.4-1%. They are bilobed nucleated granulocytes.
Basophils have histamine that cause vasodilation and inflammation, and also a heparin-like substance that is an anticoagulant of the blood. They are most numerous with allergic reaction that cause inflammation.
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