Question

what are the 3 lines of defense against pathogens?

Answer 1

First line of defense is:- Skin, tears, saliva and sweat. These act as a barrier to the entry of pathogens or any other foreign particles.

Second line of defense is:- White blood cells such as macrophages and neutrophils. There role is to recognize the foreign particles like pathogen and stimulate other lymphocytes for action.

Third line of defense is:- Antibodies, that cause the final destruction of foreign particles.