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Specific Defense Mechanism. Suman Mandal MS in Zoology(Fisheries) Uniersity of Dhaka Bangladesh suman.magician@yahoo.com , www.sumanmagician.yolasite.com. Specific Defense Mechanism. Characteristics Specificity Memory Two specific mechanisms Humoral Immune Response (HIR)
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Specific Defense Mechanism Suman Mandal MS in Zoology(Fisheries) Uniersity of Dhaka Bangladesh suman.magician@yahoo.com, www.sumanmagician.yolasite.com. suman.magician@yahoo.com
Specific Defense Mechanism • Characteristics • Specificity • Memory • Two specific mechanisms • Humoral Immune Response (HIR) • Cell-mediated Immune Response (CMIR) suman.magician@yahoo.com
Terminology • Antibodies • Protein produced in response to foreign substances • Can destroy or neutralize antigens • Antigens • Substances that can elicit a specific immune response • Pathogens • Micro-organisms that can cause diseases suman.magician@yahoo.com
Humoral immune response (HIR) • Antigens e.g. bacteria, pollen, animal fur, red blood cells etc • Characteristics • B cells are involved • Results in production of antibodies suman.magician@yahoo.com
Antibodies combat against antigen B Antigen e.g. bacteria, pollen, animal fur, red blood cells, etc Blast cell B B cell Antibody forming cell Plasma cell suman.magician@yahoo.com
Antibodies • Y-shaped • Protein in nature • Two top ends of the ‘Y’ are specific to the particular antigen • Bind to antigen • Help to destroy or eliminate antigens by • Lysis • Enhance phagocytosis • Neutralize bacterial toxins suman.magician@yahoo.com
Cell-mediated immune response (CMIR) • Antigens e.g. intracellular bacteria, viruses, foreign substances like skin, kidney etc • Characteristics • T cells are involved suman.magician@yahoo.com
T Memory cell T Kill antigen directly Antigen (e.g. bacteria, viruses, foreign substances...) T Killer T cell T cell T Lymphokines Activated T cell Macrophage Activated macrophage suman.magician@yahoo.com
Primary response • Elicited when an antigen entered into the body for the first time • Secondary response • Elicited when subsequent entry by the same antigen • Characteristics • Shorter lag period • Sharper increase and a higher level of antibodies produced • High antibody level stays longer suman.magician@yahoo.com