What is innate immunity? List the four types of barriers that protect the body from the entry of foreign agents.
The immunity which is resent at the time of birth and shows a non-specific type of defense is called Innate Immunity. The four types of barriers that protect the body from the entry of foreign agents are: (i) Physical Barriers: Skin, digestive and urinogenital tract, mucous-coated epithelium, or respiratory. (ii) Physiological Barriers: Acidity of Stomach, tears, sweat, lysozyme in saliva. (iii) Cellular Barrier: Macrophages, monocytes neutrophils, and natural killer lymphocytes. (iv) Cytokine Barriers: Interferons produced by Virally infected cells, protect the non-infected cells from further Viral infection.
