Defences of the body to pathogens and parasites

1) Primary defence:

Physical barriers-prevent pathogens entering the body

e.g. coughing/sneezing/vomiting, skin (epithelia/keratin), nose hairs, cilia in trachea, blood clotting, lysosome (mucus layer in eye), eyelashes

2) Secondary defence:

Body reacts to the presence of any pathogen (mainly phagocytosis)

e.g. antimicrobial substances, inflammation (confines and destroys microorganisms and repairs tissues), fever (inhibits microbial growth and speeds up body reactions to aid repair)

3) Tertiary defence:

Carried out by lymphocytes once the pathogen has been identified by the immune system

Non-specific immune response:
(Doesn't matter what pathogen enters)

A physical,chemical and cellular defences that prevent microorganisms from entering the body

Specific immune response:

A response to a specific pathogen, involving the action of lymphocytes and the production of antibodies