Question

In which one of the following options the two examples are not correctly matched with their particular type of innate immunity?

• A. Acid of stomach and lysozyme - Physiological barrier
• B. Polymorphonuclear leukocytes and macrophages - Cellular barrier
• C.
  Skin and mucous membranes- Physical barrier
  
• D. Interferons and insulin - Cytokine barriers

Answer 1

The correct option is D Interferons and insulin - Cytokine barriers

Innate immunity is a non-specific (not against any particular pathogen) type of defence mechanism an individual possesses by birth due to genetic and body make up. It is of different types.

Physical barriers : The structural barriers present in our body which resist infections are called physical barriers. Skin and mucus coating in our body prevent the entry of microorganisms by entrapping them which finally leads to their death.

Physiological barriers : The secretions from the body which resist infections. Saliva and tears possess lysozymes which kill bacteria by destroying their cell walls. Acid present in the stomach also helps in killing bacteria. So option c is correct as they are physiological barriers.

Cytokine barriers : The chemicals produced by the cells which resist infections. Interferons are produced by the viral infected cells to stop the multiplication of viruses.

Cellular barriers : The immune cells present in our body which resist infection. Polymorphonuclear leukocytes like neutrophils can phagocytose (cell eating) and destroy microorganisms. Macrophages formed from monocytes, eat off microorganisms, debris, dead cells etc.

Insulin is a hormone produced by the pancreas. It increases the blood sugar level. It is not a cytokine barrier.