Looking for classes? Ksquare Career Institute, Bengaluru →
To which type of barriers under innate immunity, do the saliva in the mouth and the tears from the eyes, belong?
A
Physiological barriers
B
Physical barriers
C
Cytokine barriers
D
Cellular barriers
Detailed Solution
Innate immunity is the non-specific type of defence that is present at the time of birth. It consists of four types of barriers.
Physical barriers: the skin, and the mucus coating of the epithelium lining the respiratory, gastrointestinal and urogenital tracts.
Physiological barriers: acid in the stomach, saliva in the mouth and tears from the eyes; all of these prevent microbial growth. Saliva and tears contain the enzyme lysozyme, which destroys bacterial cell walls.
Cellular barriers: certain leucocytes such as polymorpho-nuclear leucocytes (neutrophils), monocytes and natural killer cells, as well as macrophages in the tissues, which phagocytose and destroy microbes.
Cytokine barriers: virus-infected cells secrete proteins called interferons, which protect non-infected cells from further viral infection.
So saliva in the mouth and tears from the eyes belong to the physiological barriers.
Physical barriers: the skin, and the mucus coating of the epithelium lining the respiratory, gastrointestinal and urogenital tracts.
Physiological barriers: acid in the stomach, saliva in the mouth and tears from the eyes; all of these prevent microbial growth. Saliva and tears contain the enzyme lysozyme, which destroys bacterial cell walls.
Cellular barriers: certain leucocytes such as polymorpho-nuclear leucocytes (neutrophils), monocytes and natural killer cells, as well as macrophages in the tissues, which phagocytose and destroy microbes.
Cytokine barriers: virus-infected cells secrete proteins called interferons, which protect non-infected cells from further viral infection.
So saliva in the mouth and tears from the eyes belong to the physiological barriers.