Question

Explain the role of anatomical barriers of innate immunity.

Answer 1

(i) Skin: The hard, keratinised outer layer covers all external parts and effectively prevents the entry of most bacteria and viruses. 

(ii) Mucous membrane: The respiratory tract is lined by mucous membrane; cilia and fine hair filter out undesired particles in the nostrils and mucus traps the bacteria. In the trachea and bronchi, ciliary movements sweep bacteria towards the throat, from where they are expelled by coughing or sneezing. 

(iii) The mucous coating of the epithelium lining the gastrointestinal and urogenital tracts also helps trap microbes entering the body.