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Human Health and Disease — BIOLOGY STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceBIOLOGYHuman Health and Disease5 Marks
Question
Discuss the different barrier of innate immunity.
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Answer

It is accomplished by providing different types of barriers:
  1. Physical barriers: These barriers do not allow pathogens and foreign agents to enter the body, e.g., skin, mucous membranes of digestive, respiratory and urinogenital tracts trapping microorganisms.
  2. Physiological barriers: Sweat, tears, acid in the stomach and saliva prevent microbial growth.
  3. Cellular barriers: WBCs (polymorphonuclear leukocytes and monocytes, natural killer lymphocytes) and macrophages phagocytose and destroy microbes.
  4. Cytokine barriers: Interferons produced by virus-infected cells protect non-infected cells from further viral infection.

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