Immunity: Introduction, Types of Immunity, and Innate Immunity

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Introduction to Immunity

  • Immunity can be defined as the ability of the body to defend itself against disease-causing organisms.

  • It protects the body against disease or other potentially damaging foreign bodies.

  • It is a balanced state of multicellular organisms having adequate biological defense mechanism to fight infection, disease, or another unwanted biological invasion.

  • In simple words one can say that the defense mechanism of the body is called immunity.

  • It involves both specific and non-specific components.

  • Against a wide range of pathogens, the nonspecific components act as barriers or eliminators.

  • The immune system acts against a variety of threats such as viruses, bacteria, and parasites.

Introduction to Immunity

Introduction to Immunity

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Types of Immunity

Innate Immunity

  • Response is non-specific.

  • Composed of leukocytes.

  • Cell-mediated and humoral components.

  • No immunological memory.

  • Found in all forms of life.

  • Exposure leads to immediate maximal response.

Elements of Innate Immune System

Elements of innate immune system

Elements of Innate Immune System

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Adaptive Immunity

  • Pathogen and antigen specific response.

  • Composed of antigens, B cells, T cells.

  • Exposure leads to immunological memory.

  • Lag time between exposure and maximal response.

  • Cell-mediated and humoral components.

  • Found only in jawed vertebrates.

Passive Immunity

  • This is produced by antibodies produced outside the body.

  • Lasts for a short duration of time.

  • For e.g. temporary immunity is provided to a baby by antibodies present in a mother’s breast milk.

  • It may cause reactions.

  • Immunity develops immediately.

Active Immunity

  • It is a type of adaptive immunity developed due to the production of antibodies in one’s own body.

  • This immunity occurs when a person is in contact with the pathogen or its antigen.

  • There are no side-effects.

  • Immunity does not occur immediately.

Symptoms of Immune Dysfunction

  • Autoimmune disorders.

  • Painful joints and muscles.

  • Herpes (cold sore) outbreak.

  • Rhinitis or a constant runny nose.

  • Psoriasis, eczema, hives, or rashes.

  • Bowel disorders.

  • Parasite infections.

Parts of the Immune System

Parts of the Immune System

Parts of the Immune System

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