Immunity: Introduction, Types of Immunity, and Innate Immunity (For CBSE, ICSE, IAS, NET, NRA 2022)

Get unlimited access to the best preparation resource for competitive exams : get questions, notes, tests, video lectures and more- for all subjects of your exam.

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

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

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

Developed by: