Biology

 Biology 

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IMMUNITY:

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IMMUNITY:   • The ability of the host to fight the disease-causing organisms,   • conferred by the immune system.   .Immunity is of two types:   • Innate immunity   • Acquired immunity.  Innate immunity  • Non-specific type of defence,   • Present at the time of birth.   .Innate immunity is accomplished by providing different types of barriers to the entry of the foreign agents into our body.   • Innate immunity consists of four types of barriers.  These are —         • Physical barriers:                  Ø Skin                   Ø Mucus coating of the epithelium lining          • Physiological barriers:                  Ø Acid in the stomach,                  Ø saliv...
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WHAT IS INFLAMMATION ?

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 INFLAMMATION😖 INTRODUCTION DEFINITION AND CAUSES.  Inflammation is defined asthe local response of living mammalian tissues to injury dueto any agent. It is a body defense reaction in order to eliminateor limit the spread of injurious agent, followed by removal of the necrosed cells and tissues. The agents causing inflammation may be as under: 1. Infective agents like bacteria, viruses and their toxins, fungi, parasites. 2. Immunological agents like cell-mediated and antigenantibody reactions. 3. Physical agents like heat, cold, radiation, mechanical trauma. 4. Chemical agents like organic and inorganic poisons. 5. Inert materials such as foreign bodies. Thus, inflammation is distinct from infection—while inflammation is a protective response by the body to variety of etiologic agents (infectious or non-infectious), while infection is invasion into the body by harmful microbes and their resultant ill-effects by toxins. Inflammation involves 2 basic processes with some overla...
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VACCINATION | small pox variola vaccine |hepatitis-B vaccine |vaccine

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 VACCINATION       • In vaccination, a preparation of antigenic proteins of pathogen or inactivated/weakened pathogen (vaccine) are introduced into the body.       • The antibodies produced in the body against these antigens would neutralise the pathogenic agents during actual infection.                • The vaccines also generate memory – B and T-cells that recognise the pathogen quickly on subsequent exposure and kill the invaders with a massive production of antibodies.         Production of large scale of vaccine become possible through DNA recombinant technology which allowed the production of antigenic polypeptide(vaccine) in bacteria and yeast.     Hepatitis B vaccine is produced from yeast through DNA recombination technology for large scale immunisation. 
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