Immune Defense Systems

The human immune system can be divided into two main components:

Non-Specific Defenses:

these are general means which resist all types of pathogens or 'baddies'

skin - physical barrier

oil/sweat glands - acidic barrier

ciliated mucous membranes - physical sweepers of airborne pathogens

gastric fluid - acid/chemical barrier against food-borne pathogens

natural bacteria flora - acts as surface competition for foreign bacteria

macrophages - act like Pac-Man in the blood to gobble up foreign bodies.

complement system - 20 plasma proteins which act like tag-alongs on foreign bodies so macrophages can find them faster

Specific Defenses:

a very complex system, wherer the presence of a pathogen causes antibody production, which aids in the response. Unfortunately in takes some time for the production to occur so some antibodies are stored in the lymphatic system so if the same pathogen infects a second time, the immune response will be fast.